@Shardik talkinghead was working on a plugin for this using nowjs
but he hasn't been here in a while so I don't know if he gave up or is just busy.
You can read about it here:Multiplayer Demo in C2
If you know php, and mysql you could probably make it by using the AJAX plugin in C2.
@Jayjay that looks cool it kind of reminds me of The Palace
it was pretty popular back in the 90's.