If you're on the main page of the forum, or, the index, you'll notice a box before the actual forums! You can type a message in there! Woohoo!
It's like a chatroom, basically. You can leave a message, and come back later and see if there are any new ones. There's also a separate page you can access where you can interact with just the chatbox.
Enjoy!
New: chatbox!
Re: New: chatbox!
mChat has been removed, as i believe it was a factor in causing session issues.