This is the code I wrote as part of my MIX 11 talk on WebSockets.
I don't have a license to redistribute the two binaries that I reference:
But these are included in the HTML5 Labs WebSocket prototype.
Once the install is complete, you'll have the prototype bits at: C:\Program Files (x86)\Microsoft SDKs\WCF WebSockets or C:\Program Files\Microsoft SDKs\WCF WebSockets if you are on a 32-bit OS.
If you are going to use the Silverlight plugin to simulate WebSockets, you'll need to drop the clientaccesspolicy.xml file (found in the bin folder) into your c:\inetpub\wwwroot folder.
This demo uses the 07 prototype.
You can use a private build of Firefox with support for 07 WebSockets.