diff --git a/src/java/com/threerings/presents/client/BlockingCommunicator.java b/src/java/com/threerings/presents/client/BlockingCommunicator.java
index 02536cae8..f29a0e40b 100644
--- a/src/java/com/threerings/presents/client/BlockingCommunicator.java
+++ b/src/java/com/threerings/presents/client/BlockingCommunicator.java
@@ -398,8 +398,9 @@ public class BlockingCommunicator extends Communicator
             if (wrote != buffer.limit()) {
                 log.warning("Aiya! Couldn't write entire message", "msg", msg,
                             "size", buffer.limit(), "wrote", wrote);
-//             } else {
+            } else {
 //                 Log.info("Wrote " + wrote + " bytes.");
+                _client.getMessageTracker().messageSent(false, wrote, msg);
             }
 
         } finally {
@@ -443,6 +444,9 @@ public class BlockingCommunicator extends Communicator
 
         // send the datagram
         _datagramChannel.write(buf);
+
+        // notify the tracker
+        _client.getMessageTracker().messageSent(true, size, msg);
     }
 
     /**
@@ -460,10 +464,12 @@ public class BlockingCommunicator extends Communicator
         }
 
         try {
+            int size = _fin.available();
             DownstreamMessage msg = (DownstreamMessage)_oin.readObject();
             if (debugLogMessages()) {
                 log.info("RECEIVE " + msg);
             }
+            _client.getMessageTracker().messageReceived(false, size, msg);
             return msg;
 
         } catch (ClassNotFoundException cnfe) {
@@ -480,7 +486,8 @@ public class BlockingCommunicator extends Communicator
     {
         // clear the buffer and read a datagram
         _buf.clear();
-        if (_datagramChannel.read(_buf) <= 0) {
+        int size = _datagramChannel.read(_buf);
+        if (size <= 0) {
             throw new IOException("No datagram available to read.");
         }
         _buf.flip();
@@ -494,6 +501,7 @@ public class BlockingCommunicator extends Communicator
             if (debugLogMessages()) {
                 log.info("DATAGRAM " + msg);
             }
+            _client.getMessageTracker().messageReceived(true, size, msg);
             return msg;
 
         } catch (ClassNotFoundException cnfe) {
diff --git a/src/java/com/threerings/presents/client/Client.java b/src/java/com/threerings/presents/client/Client.java
index c033e5f6d..14444f633 100644
--- a/src/java/com/threerings/presents/client/Client.java
+++ b/src/java/com/threerings/presents/client/Client.java
@@ -227,6 +227,17 @@ public class Client
         }
     }
 
+    /**
+     * Installs (or clears) a message tracker that will be notified on message transmission and
+     * receipt for the purpose of statistics tracking.
+     *
+     * @param tracker the new tracker to install, or <code>null</code> to clear the tracker.
+     */
+    public void setMessageTracker (MessageTracker tracker)
+    {
+        _messageTracker = (tracker == null) ? MessageTracker.NOOP : tracker;
+    }
+
     /**
      * Returns the data associated with our authentication response. Users of the Presents system
      * may wish to communicate authentication related information to their client by extending and
@@ -676,6 +687,14 @@ public class Client
         return _outThrottle;
     }
 
+    /**
+     * Returns a reference to the message tracker to notify on message transmission and receipt.
+     */
+    protected MessageTracker getMessageTracker ()
+    {
+        return _messageTracker;
+    }
+
     /**
      * Called every five seconds; ensures that we ping the server if we haven't communicated in a
      * long while and periodically resyncs the client and server clock deltas.
@@ -1028,6 +1047,9 @@ public class Client
     /** Our outgoing message throttle. */
     protected Throttle _outThrottle = new Throttle(DEFAULT_MSGS_PER_SECOND, 1000L);
 
+    /** The tracker to notify on message transmission or receipt. */
+    protected volatile MessageTracker _messageTracker = MessageTracker.NOOP;
+
     /** How often we recompute our time offset from the server. */
     protected static final long CLOCK_SYNC_INTERVAL = 600 * 1000L;
 }
diff --git a/src/java/com/threerings/presents/client/MessageTracker.java b/src/java/com/threerings/presents/client/MessageTracker.java
new file mode 100644
index 000000000..7684c32df
--- /dev/null
+++ b/src/java/com/threerings/presents/client/MessageTracker.java
@@ -0,0 +1,52 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2009 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.presents.client;
+
+import com.threerings.presents.net.DownstreamMessage;
+import com.threerings.presents.net.UpstreamMessage;
+
+/**
+ * Used to listen to low-level message handling for the purpose of statistics tracking.  Methods
+ * must be thread-safe.
+ */
+public interface MessageTracker
+{
+    /**
+     * An implementation of the interface that does nothing.
+     */
+    public static final MessageTracker NOOP = new MessageTracker() {
+        public void messageSent (boolean datagram, int size, UpstreamMessage msg) {
+        }
+        public void messageReceived (boolean datagram, int size, DownstreamMessage msg) {
+        }
+    };
+
+    /**
+     * Notes that a message has been sent.
+     */
+    public void messageSent (boolean datagram, int size, UpstreamMessage msg);
+
+    /**
+     * Notes that a message has been received.
+     */
+    public void messageReceived (boolean datagram, int size, DownstreamMessage msg);
+}