Most of you have probably already noticed the forum chat window.
A word of caution, if you use it remember its an open area. To see what i mean try pressing the 'archive' button and it'll bring up old conversations.
To be honest - its not the best chat system in the world and is just a temporary measure. It might help reduce the conversational off topic posts within the forums though. The intent is to have a decent chat system on the new site which will replace this one.