diff --git a/src/as/com/threerings/io/SimpleStreamableObject.as b/src/as/com/threerings/io/SimpleStreamableObject.as
index 999e51fbb..db8ef6c69 100644
--- a/src/as/com/threerings/io/SimpleStreamableObject.as
+++ b/src/as/com/threerings/io/SimpleStreamableObject.as
@@ -21,9 +21,7 @@
 
 package com.threerings.io {
 
-import com.threerings.util.ClassUtil;
-import com.threerings.util.StringBuilder;
-import com.threerings.util.StringUtil;
+import com.threerings.util.Joiner;
 
 /**
  * A simple serializable object implements the {@link Streamable}
@@ -49,19 +47,18 @@ public class SimpleStreamableObject implements Streamable
      */
     public function toString () :String
     {
-        var buf :StringBuilder = new StringBuilder("[");
-        buf.append(ClassUtil.tinyClassName(this)).append("(");
-        toStringBuilder(buf);
-        return buf.append(")]").toString();
+        var j :Joiner = Joiner.createFor(this);
+        toStringJoiner(j);
+        return j.toString();
     }
 
     /**
      * Handles the toString-ification of all public members. Derived
      * classes can override and include non-public members if desired.
      */
-    protected function toStringBuilder (buf :StringBuilder): void
+    protected function toStringJoiner (j :Joiner): void
     {
-        StringUtil.fieldsToString(buf, this);
+        j.addFields(this);
     }
 }
 }
diff --git a/src/as/com/threerings/presents/dobj/AttributeChangedEvent.as b/src/as/com/threerings/presents/dobj/AttributeChangedEvent.as
index 4e940ea7c..f3b9aaf17 100644
--- a/src/as/com/threerings/presents/dobj/AttributeChangedEvent.as
+++ b/src/as/com/threerings/presents/dobj/AttributeChangedEvent.as
@@ -25,7 +25,7 @@ import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
 import com.threerings.util.Boxed;
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * An attribute changed event is dispatched when a single attribute of a
@@ -107,11 +107,10 @@ public class AttributeChangedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("CHANGE:");
-        super.toStringBuf(buf);
-        buf.append(", value=", _value);
+        super.toStringJoiner(j);
+        j.add("value", _value);
     }
 
     override public function writeObject (out :ObjectOutputStream) :void
diff --git a/src/as/com/threerings/presents/dobj/CompoundEvent.as b/src/as/com/threerings/presents/dobj/CompoundEvent.as
index 18e836796..f5cbfe06f 100644
--- a/src/as/com/threerings/presents/dobj/CompoundEvent.as
+++ b/src/as/com/threerings/presents/dobj/CompoundEvent.as
@@ -24,8 +24,8 @@ package com.threerings.presents.dobj {
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
+import com.threerings.util.Joiner;
 import com.threerings.util.StreamableArrayList;
-import com.threerings.util.StringBuilder;
 
 /**
  * Used to manage and submit groups of events on a collection of distributed objects in a single
@@ -90,15 +90,10 @@ public class CompoundEvent extends DEvent
     }
 
     // from DObject
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("COMPOUND:");
-        super.toStringBuf(buf);
-
-        var nn :int = _events.size();
-        for (var ii :int = 0; ii < nn; ii++) {
-            buf.append(", ", _events.get(ii));
-        }
+        super.toStringJoiner(j);
+        j.addArgsArray(_events.asArray());
     }
 
     // from DObject
diff --git a/src/as/com/threerings/presents/dobj/DEvent.as b/src/as/com/threerings/presents/dobj/DEvent.as
index c14907285..afb9e195a 100644
--- a/src/as/com/threerings/presents/dobj/DEvent.as
+++ b/src/as/com/threerings/presents/dobj/DEvent.as
@@ -25,7 +25,7 @@ import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 import com.threerings.io.Streamable;
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 public /* abstract */ class DEvent
     implements Streamable
@@ -96,21 +96,19 @@ public /* abstract */ class DEvent
      */
     public function toString () :String
     {
-        var buf :StringBuilder = new StringBuilder();
-        buf.append("[");
-        toStringBuf(buf);
-        buf.append("]");
-        return buf.toString();
+        var j :Joiner = Joiner.createFor(this);
+        toStringJoiner(j);
+        return j.toString();
     }
 
     /**
      * This should be overridden by derived classes (which should be sure
-     * to call <code>super.toString()</code>) to append the derived class
-     * specific event information to the string buffer.
+     * to call <code>super.toStringJoiner()</code> first) to append the derived class
+     * specific event information onto the String representation.
      */
-    protected function toStringBuf (buf :StringBuilder) :void
+    protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("targetOid=", _toid);
+        j.add("targetOid", _toid);
     }
 
     /** The oid of the object that is the target of this event. */
diff --git a/src/as/com/threerings/presents/dobj/DObject.as b/src/as/com/threerings/presents/dobj/DObject.as
index 981349b0e..f1d31fa86 100644
--- a/src/as/com/threerings/presents/dobj/DObject.as
+++ b/src/as/com/threerings/presents/dobj/DObject.as
@@ -26,8 +26,8 @@ import flash.errors.IllegalOperationError;
 import flash.events.EventDispatcher;
 
 import com.threerings.util.ClassUtil;
+import com.threerings.util.Joiner;
 import com.threerings.util.Log;
-import com.threerings.util.StringBuilder;
 
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
@@ -157,34 +157,33 @@ public class DObject // extends EventDispatcher
      */
     public function which () :String
     {
-        var buf :StringBuilder = new StringBuilder();
-        whichBuf(buf);
-        return buf.toString();
+        var j :Joiner = Joiner.createFor(this);
+        whichJoiner(j);
+        return j.toString();
     }
 
     /**
      * Used to briefly describe this distributed object.
      */
-    protected function whichBuf (buf :StringBuilder) :void
+    protected function whichJoiner (j :Joiner) :void
     {
-        buf.append(ClassUtil.shortClassName(this), ":", _oid);
+        j.addArgs(_oid);
     }
 
     // documentation inherited
     public function toString () :String
     {
-        var buf :StringBuilder = new StringBuilder("[");
-        toStringBuf(buf);
-        buf.append("]");
-        return buf.toString();
+        var j :Joiner = Joiner.createFor(this);
+        toStringJoiner(j);
+        return j.toString();
     }
 
     /**
      * Generates a string representation of this object.
      */
-    public function toStringBuf (buf :StringBuilder) :void
+    public function toStringJoiner (j :Joiner) :void
     {
-        buf.append("oid=", _oid);
+        j.add("oid", _oid);
     }
 
     /**
diff --git a/src/as/com/threerings/presents/dobj/DSet.as b/src/as/com/threerings/presents/dobj/DSet.as
index 2d8e59468..de6dc48ed 100644
--- a/src/as/com/threerings/presents/dobj/DSet.as
+++ b/src/as/com/threerings/presents/dobj/DSet.as
@@ -26,7 +26,6 @@ import com.threerings.util.Cloneable;
 import com.threerings.util.Equalable;
 import com.threerings.util.Iterator;
 import com.threerings.util.Log;
-import com.threerings.util.StringBuilder;
 import com.threerings.util.Util;
 
 import com.threerings.io.ObjectInputStream;
@@ -225,10 +224,7 @@ public class DSet
      */
     public function toString () :String
     {
-        var buf :StringBuilder = new StringBuilder("(");
-        buf.append(_entries.toString());
-        buf.append(")");
-        return buf.toString();
+        return "(" + _entries.toString() + ")";
     }
 
     // documentation inherited from interface Streamable
diff --git a/src/as/com/threerings/presents/dobj/ElementUpdatedEvent.as b/src/as/com/threerings/presents/dobj/ElementUpdatedEvent.as
index 48d006396..f186a36e1 100644
--- a/src/as/com/threerings/presents/dobj/ElementUpdatedEvent.as
+++ b/src/as/com/threerings/presents/dobj/ElementUpdatedEvent.as
@@ -25,7 +25,7 @@ import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
 import com.threerings.util.Boxed;
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * An element updated event is dispatched when an element of an array
@@ -132,12 +132,10 @@ public class ElementUpdatedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("UPDATE:");
-        super.toStringBuf(buf);
-        buf.append(", value=", _value);
-        buf.append(", index=", _index);
+        super.toStringJoiner(j);
+        j.add("value", _value, "index", _index);
     }
 
     protected var _value :Object;
diff --git a/src/as/com/threerings/presents/dobj/EntryAddedEvent.as b/src/as/com/threerings/presents/dobj/EntryAddedEvent.as
index c4d7423ce..9931d2b5e 100644
--- a/src/as/com/threerings/presents/dobj/EntryAddedEvent.as
+++ b/src/as/com/threerings/presents/dobj/EntryAddedEvent.as
@@ -24,8 +24,8 @@ package com.threerings.presents.dobj {
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
+import com.threerings.util.Joiner;
 import com.threerings.util.Log;
-import com.threerings.util.StringBuilder;
 
 /**
  * An entry added event is dispatched when an entry is added to a {@link
@@ -88,11 +88,10 @@ public class EntryAddedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("ELADD:");
-        super.toStringBuf(buf);
-        buf.append(", entry=", _entry);
+        super.toStringJoiner(j);
+        j.add("entry", _entry);
     }
 
     override public function writeObject (out :ObjectOutputStream) :void
diff --git a/src/as/com/threerings/presents/dobj/EntryRemovedEvent.as b/src/as/com/threerings/presents/dobj/EntryRemovedEvent.as
index dcb08cd83..067fdaa1b 100644
--- a/src/as/com/threerings/presents/dobj/EntryRemovedEvent.as
+++ b/src/as/com/threerings/presents/dobj/EntryRemovedEvent.as
@@ -25,8 +25,8 @@ import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
 import com.threerings.util.Boxed;
+import com.threerings.util.Joiner;
 import com.threerings.util.Log;
-import com.threerings.util.StringBuilder;
 
 /**
  * An entry removed event is dispatched when an entry is removed from a
@@ -107,11 +107,10 @@ public class EntryRemovedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("ELREM:");
-        super.toStringBuf(buf);
-        buf.append(", key=", _key);
+        super.toStringJoiner(j);
+        j.add("key", _key);
     }
 
     override public function writeObject (out :ObjectOutputStream) :void
diff --git a/src/as/com/threerings/presents/dobj/EntryUpdatedEvent.as b/src/as/com/threerings/presents/dobj/EntryUpdatedEvent.as
index e51e45614..90bb15bd8 100644
--- a/src/as/com/threerings/presents/dobj/EntryUpdatedEvent.as
+++ b/src/as/com/threerings/presents/dobj/EntryUpdatedEvent.as
@@ -24,8 +24,8 @@ package com.threerings.presents.dobj {
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
+import com.threerings.util.Joiner;
 import com.threerings.util.Log;
-import com.threerings.util.StringBuilder;
 
 /**
  * An entry updated event is dispatched when an entry of a {@link DSet} is
@@ -89,8 +89,7 @@ public class EntryUpdatedEvent extends NamedEvent
             _oldEntry = dset.update(_entry);
             if (_oldEntry == null) {
                 // complain if we didn't update anything
-                Log.getLog(this).warning("No matching entry to update " +
-                    "[entry=" + this + ", set=" + dset + "].");
+                Log.getLog(this).warning("No matching entry to update", "entry", this, "set", dset);
                 return false;
             }
         }
@@ -106,11 +105,10 @@ public class EntryUpdatedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("ELUPD:");
-        super.toStringBuf(buf);
-        buf.append(", entry=", _entry);
+        super.toStringJoiner(j);
+        j.add("entry", _entry);
     }
 
     override public function writeObject (out :ObjectOutputStream) :void
diff --git a/src/as/com/threerings/presents/dobj/InvocationNotificationEvent.as b/src/as/com/threerings/presents/dobj/InvocationNotificationEvent.as
index 7e4e489c7..b5325aade 100644
--- a/src/as/com/threerings/presents/dobj/InvocationNotificationEvent.as
+++ b/src/as/com/threerings/presents/dobj/InvocationNotificationEvent.as
@@ -25,7 +25,7 @@ import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 import com.threerings.io.TypedArray;
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * Used to dispatch an invocation notification from the server to a
@@ -103,13 +103,10 @@ public class InvocationNotificationEvent extends DEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("INOT:");
-        super.toStringBuf(buf);
-        buf.append(", rcvId=", _receiverId);
-        buf.append(", methodId=", _methodId);
-        buf.append(", args=", _args);
+        super.toStringJoiner(j);
+        j.add("rcvId", _receiverId, "methodId", _methodId, "args", _args);
     }
 
     // documentation inherited
diff --git a/src/as/com/threerings/presents/dobj/InvocationRequestEvent.as b/src/as/com/threerings/presents/dobj/InvocationRequestEvent.as
index 8cc8904d2..557c1215a 100644
--- a/src/as/com/threerings/presents/dobj/InvocationRequestEvent.as
+++ b/src/as/com/threerings/presents/dobj/InvocationRequestEvent.as
@@ -24,7 +24,7 @@ package com.threerings.presents.dobj {
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * Used to dispatch an invocation request from the client to the server.
@@ -99,13 +99,10 @@ public class InvocationRequestEvent extends DEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("IREQ:");
-        super.toStringBuf(buf);
-        buf.append(", code=", _invCode);
-        buf.append(", methodId=", _methodId);
-        buf.append(", args=", _args);
+        super.toStringJoiner(j);
+        j.add("code", _invCode, "methodId", _methodId, "args", _args);
     }
 
     // documentation inherited from interface Streamable
diff --git a/src/as/com/threerings/presents/dobj/InvocationResponseEvent.as b/src/as/com/threerings/presents/dobj/InvocationResponseEvent.as
index d52d2c12e..fd0ebb1c7 100644
--- a/src/as/com/threerings/presents/dobj/InvocationResponseEvent.as
+++ b/src/as/com/threerings/presents/dobj/InvocationResponseEvent.as
@@ -24,7 +24,7 @@ package com.threerings.presents.dobj {
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * Used to dispatch an invocation response from the server to the client.
@@ -99,13 +99,10 @@ public class InvocationResponseEvent extends DEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("IRSP:");
-        super.toStringBuf(buf);
-        buf.append(", reqid=", _requestId);
-        buf.append(", methodId=", _methodId);
-        buf.append(", args=", _args);
+        super.toStringJoiner(j);
+        j.add("reqId", _requestId, "methodId", _methodId, "args", _args);
     }
 
     // documentation inherited
diff --git a/src/as/com/threerings/presents/dobj/MessageEvent.as b/src/as/com/threerings/presents/dobj/MessageEvent.as
index 4ed93f7c0..1563c89c9 100644
--- a/src/as/com/threerings/presents/dobj/MessageEvent.as
+++ b/src/as/com/threerings/presents/dobj/MessageEvent.as
@@ -26,7 +26,7 @@ import com.threerings.io.ObjectOutputStream;
 import com.threerings.io.TypedArray;
 
 import com.threerings.util.Boxed;
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * A message event is used to dispatch a message to all subscribers of a
@@ -97,11 +97,10 @@ public class MessageEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("MSG:");
-        super.toStringBuf(buf);
-        buf.append(", args=", _args);
+        super.toStringJoiner(j);
+        j.add("args", _args);
     }
 
     // documentation inherited
diff --git a/src/as/com/threerings/presents/dobj/NamedEvent.as b/src/as/com/threerings/presents/dobj/NamedEvent.as
index fa319eb81..5c19048a0 100644
--- a/src/as/com/threerings/presents/dobj/NamedEvent.as
+++ b/src/as/com/threerings/presents/dobj/NamedEvent.as
@@ -21,7 +21,7 @@
 
 package com.threerings.presents.dobj {
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
@@ -53,10 +53,10 @@ public /* abstract */ class NamedEvent extends DEvent
         return _name;
     }
 
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        super.toStringBuf(buf);
-        buf.append(", name=", _name);
+        super.toStringJoiner(j);
+        j.add("name", _name);
     }
 
     override public function writeObject (out :ObjectOutputStream) :void
diff --git a/src/as/com/threerings/presents/dobj/ObjectAddedEvent.as b/src/as/com/threerings/presents/dobj/ObjectAddedEvent.as
index b9971d502..7d072a845 100644
--- a/src/as/com/threerings/presents/dobj/ObjectAddedEvent.as
+++ b/src/as/com/threerings/presents/dobj/ObjectAddedEvent.as
@@ -24,7 +24,7 @@ package com.threerings.presents.dobj {
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 /**
  * An object added event is dispatched when an object is added to an
@@ -97,11 +97,10 @@ public class ObjectAddedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("OBJADD:");
-        super.toStringBuf(buf);
-        buf.append(", oid=", _oid);
+        super.toStringJoiner(j);
+        j.add("oid", _oid);
     }
 
     protected var _oid :int;
diff --git a/src/as/com/threerings/presents/dobj/ObjectDestroyedEvent.as b/src/as/com/threerings/presents/dobj/ObjectDestroyedEvent.as
index 714916866..5cb9d14f5 100644
--- a/src/as/com/threerings/presents/dobj/ObjectDestroyedEvent.as
+++ b/src/as/com/threerings/presents/dobj/ObjectDestroyedEvent.as
@@ -21,8 +21,6 @@
 
 package com.threerings.presents.dobj {
 
-import com.threerings.util.StringBuilder;
-
 /**
  * An object destroyed event is dispatched when an object has been removed
  * from the distributed object system. It can also be constructed to
@@ -59,12 +57,5 @@ public class ObjectDestroyedEvent extends DEvent
             listener.objectDestroyed(this);
         }
     }
-
-    // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
-    {
-        buf.append("DESTROY:");
-        super.toStringBuf(buf);
-    }
 }
 }
diff --git a/src/as/com/threerings/presents/dobj/ObjectRemovedEvent.as b/src/as/com/threerings/presents/dobj/ObjectRemovedEvent.as
index 2ed110bbc..0d2fb2fde 100644
--- a/src/as/com/threerings/presents/dobj/ObjectRemovedEvent.as
+++ b/src/as/com/threerings/presents/dobj/ObjectRemovedEvent.as
@@ -21,7 +21,7 @@
 
 package com.threerings.presents.dobj {
 
-import com.threerings.util.StringBuilder;
+import com.threerings.util.Joiner;
 
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
@@ -99,11 +99,10 @@ public class ObjectRemovedEvent extends NamedEvent
     }
 
     // documentation inherited
-    override protected function toStringBuf (buf :StringBuilder) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        buf.append("OBJREM:");
-        super.toStringBuf(buf);
-        buf.append(", oid=", _oid);
+        super.toStringJoiner(j);
+        j.add("oid", _oid);
     }
 
     protected var _oid :int;
diff --git a/src/as/com/threerings/presents/dobj/OidList.as b/src/as/com/threerings/presents/dobj/OidList.as
index 27bdd7bba..ed6f4484d 100644
--- a/src/as/com/threerings/presents/dobj/OidList.as
+++ b/src/as/com/threerings/presents/dobj/OidList.as
@@ -29,8 +29,6 @@ import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 import com.threerings.io.TypedArray;
 
-import com.threerings.util.StringBuilder;
-
 /**
  * An oid list is used to store lists of object ids. The list will not
  * allow duplicate ids. This class is not synchronized, with the
@@ -127,11 +125,7 @@ public class OidList
 
     public function toString () :String
     {
-        var buf :StringBuilder = new StringBuilder();
-        buf.append("{");
-        buf.append(_oids.toString());
-        buf.append("}");
-        return buf.toString();
+        return "{" + _oids.toString() + "}";
     }
 
     private var _oids :TypedArray;
diff --git a/src/as/com/threerings/presents/net/Credentials.as b/src/as/com/threerings/presents/net/Credentials.as
index 4f5759913..507968863 100644
--- a/src/as/com/threerings/presents/net/Credentials.as
+++ b/src/as/com/threerings/presents/net/Credentials.as
@@ -23,67 +23,19 @@ package com.threerings.presents.net {
 
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
-import com.threerings.io.Streamable;
+import com.threerings.io.SimpleStreamableObject;
 
-public /* abstract */ class Credentials
-    implements Streamable
+public /* abstract */ class Credentials extends SimpleStreamableObject
 {
     public function Credentials ()
     {
     }
 
     // from interface Streamable
-    public function writeObject (out :ObjectOutputStream) :void
-        //throws IOError
-    {
-        // nada
-    }
-
-    // from interface Streamable
-    public function readObject (ins :ObjectInputStream) :void
+    override public function readObject (ins :ObjectInputStream) :void
         //throws IOError
     {
         throw new Error(); // we never read Creds on the client
     }
-
-    /*
-    // main
-    public function toString (joiner :Joiner = null) :String
-    {
-        if (joiner == null) {
-            return toString(new Joiner("ClassName"));
-        }
-        return joiner.add("baz", bit, "count", 33).toString();
-    }
-
-    // subclass
-    override public function toString (joiner :Joiner = null) :String
-    {
-        if (joiner != null) {
-            joiner.add("foo", bar);
-        }
-        return super.toString(joiner);
-    }
-
-
-    // -----
-
-    public function toString () :String
-    {
-        return join(new Joiner(this)).toString();
-    }
-
-    protected function join (joiner :Joiner) :Joiner
-    {
-        return joiner.add(
-            "baz", bit, "count", 33);
-    }
-
-    override protected join (joiner :Joiner) :Joiner
-    {
-        return super.join(joiner).add(
-            "foo", bar);
-    }
-    */
 }
 }
diff --git a/src/as/com/threerings/presents/net/ServiceCreds.as b/src/as/com/threerings/presents/net/ServiceCreds.as
index 45158e557..7398f2c64 100644
--- a/src/as/com/threerings/presents/net/ServiceCreds.as
+++ b/src/as/com/threerings/presents/net/ServiceCreds.as
@@ -26,6 +26,8 @@ import com.adobe.crypto.MD5;
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
 
+import com.threerings.util.Joiner;
+
 /**
  * Extends the basic credentials to provide bureau-specific fields.
  */
@@ -60,9 +62,10 @@ public class ServiceCreds extends Credentials
     }
 
     // from Object
-    public function toString () :String
+    override protected function toStringJoiner (j :Joiner) :void
     {
-        return "[id=" + clientId + ", token=" + _authToken + "]";
+        super.toStringJoiner(j);
+        j.add("token", _authToken);
     }
 
     /**
diff --git a/src/as/com/threerings/presents/net/UsernamePasswordCreds.as b/src/as/com/threerings/presents/net/UsernamePasswordCreds.as
index eb8cd5c72..9bcce611e 100644
--- a/src/as/com/threerings/presents/net/UsernamePasswordCreds.as
+++ b/src/as/com/threerings/presents/net/UsernamePasswordCreds.as
@@ -21,8 +21,8 @@
 
 package com.threerings.presents.net {
 
+import com.threerings.util.Joiner;
 import com.threerings.util.Name;
-import com.threerings.util.StringBuilder;
 
 import com.threerings.io.ObjectInputStream;
 import com.threerings.io.ObjectOutputStream;
@@ -55,26 +55,10 @@ public class UsernamePasswordCreds extends Credentials
         out.writeField(_password);
     }
 
-    // from Credentials
-    override public function readObject (ins :ObjectInputStream) :void
+    override protected function toStringJoiner (j :Joiner) :void
     {
-    	_username = Name(ins.readObject());
-        _password = (ins.readField(String) as String);
-    }
-
-    // from Object
-    public function toString () :String
-    {
-        var buf :StringBuilder = new StringBuilder("[");
-        toStringBuf(buf);
-        buf.append("]");
-        return buf.toString();
-    }
-
-    protected function toStringBuf (buf :StringBuilder) :void
-    {
-        buf.append("username=", _username);
-        buf.append(", password=", _password);
+        j.add("username", _username, "password", _password);
+        super.toStringJoiner(j);
     }
 
     protected var _username :Name;
diff --git a/src/as/com/threerings/util/MessageBundle.as b/src/as/com/threerings/util/MessageBundle.as
index 60af788f4..1c967f061 100644
--- a/src/as/com/threerings/util/MessageBundle.as
+++ b/src/as/com/threerings/util/MessageBundle.as
@@ -302,25 +302,24 @@ public class MessageBundle
     {
         args = Util.unfuckVarargs(args);
 
-        var buf :StringBuilder = new StringBuilder();
-        buf.append(key, "|");
+        var s :String = key + "|";
         for (var ii :int = 0; ii < args.length; ii++) {
             if (ii > 0) {
-                buf.append("|");
+                s += "|";
             }
             var arg :String = String(args[ii]);
             for (var p :int = 0; p < arg.length; p++) {
                 var ch :String = arg.charAt(p);
                 if (ch == "|") {
-                    buf.append("\\!");
+                    s += "\\!";
                 } else if (ch == "\\") {
-                    buf.append("\\\\");
+                    s += "\\\\";
                 } else {
-                    buf.append(ch);
+                    s += ch;
                 }
             }
         }
-        return buf.toString();
+        return s;
     }
 
     /**
@@ -404,19 +403,18 @@ public class MessageBundle
             return val;
         }
 
-        var buf :StringBuilder = new StringBuilder();
+        var s :String = "";
         for (var ii :int = 0; ii < val.length; ii++) {
             var ch :String = val.charAt(ii);
             if (ch != "\\" || ii == val.length-1) {
-                buf.append(ch);
+                s += ch;
             } else {
                 // look at the next character
                 ch = val.charAt(++ii);
-                buf.append((ch == "!") ? "|" : ch);
+                s += (ch == "!") ? "|" : ch;
             }
         }
-
-        return buf.toString();
+        return s;
     }
 
     /** The message manager via whom we'll resolve fully qualified