diff --git a/src/as/com/threerings/util/Config.as b/src/as/com/threerings/util/Config.as
index a30d04a5e..b059e1249 100644
--- a/src/as/com/threerings/util/Config.as
+++ b/src/as/com/threerings/util/Config.as
@@ -1,6 +1,9 @@
 package com.threerings.util {
 
+import flash.events.NetStatusEvent;
+
 import flash.net.SharedObject;
+import flash.net.SharedObjectFlushStatus;
 
 public class Config
 {
@@ -40,6 +43,46 @@ public class Config
         _so.flush(); // flushing is not strictly necessary
     }
 
+    /**
+     * Ensure that we can store preferences up to the specified size.
+     * Note that calling this method may pop up a dialog to the user, asking
+     * them if it's ok to increase the capacity. The result listener may
+     * never be called if the user doesn't answer the pop-up.
+     *
+     * @param rl an optional listener that will be informed as to whether
+     * the request succeeded.
+     */
+    public function ensureCapacity (kilobytes :int, rl :ResultListener) :void
+    {
+        // flush with the size, see if we're cool
+        var result :String = _so.flush(1024 * kilobytes);
+        if (rl == null) {
+            return;
+        }
+
+        // success
+        if (result == SharedObjectFlushStatus.FLUSHED) {
+            rl.requestCompleted(this);
+            return;
+        }
+
+        // otherwise we'll hear back in a sec
+        var thisConfig :Config = this;
+        var listener :Function = function (evt :NetStatusEvent) :void {
+                // TODO: as of beta3 there is a bug where the status
+                // is always "SharedObject.Flush.Failed", even on success
+                //trace("================[" + evt.info.code + "]");
+                if ("SharedObject.Flush.Success" == evt.info.code) {
+                    rl.requestCompleted(thisConfig);
+                } else {
+                    rl.requestFailed(new Error(String(evt.info.code)));
+                }
+                _so.removeEventListener(NetStatusEvent.NET_STATUS, listener);
+            };
+
+        _so.addEventListener(NetStatusEvent.NET_STATUS, listener);
+    }
+
     /** The shared object that contains our preferences. */
     protected var _so :SharedObject;
 }