I finally got around to installing a new chat room to our forum. It's based on phpFreeChat, and it seems to work very well. It's got the similar smilies to MSN Messenger, and its easy to use with plenty of features. I think it can even use private messages if you want to chat with someone else on the side not viewable to the main chat users, but I haven't tried it yet.
It is also interfaced with the username and password of the main forum, so this means if you are already logged in to the forum, it will log you into the chat with your username. If you are not logged in to the forum, if you click on the link, it will bring you to the log in screen for the forum, then you will need to re-enter the chat room by clicking on the chat room link again. If you're not registered on the forum, you won't be able to use the chat room.
The link to the chat room is on the upper right part of the screen of the forum, next to the search and FAQ links.
Or, you can access it here: Chat Room
So check it out, and let me know if you have any problems or suggestions.
Have fun!