It's a good idea. I have designed 4 forums so far, 2 of which have had live chatroom, 2 of which are still active. The hint is there =P.
They are great function if you get the right software, and they can be a lot more fun than forums because the witty remarks are so much quicker =].
If it goes ahead give me a PM and I can advise Shaun or whoever on software, the chatboxs don't work, but the chatrooms do.