gsstellacci@hotmail.com
Actually, I think that a better alternative would be to have an IRC channel, say with BeyondIRC Servers. To connect, you can implement an IRC Java applet right into the website. That would be most ecconomical, so if you wanted to chat, just click the "Chat" button on the top, and you'd be in a chat room integrated into the layout of this site. Or, you can use mIRC, an IRC client.
It is advisable not to be with MSN, they would control too much, and to find the chat room is too much pain. Having one integrated right into the site is the best solution. And with IRC, you can easily register usernames and channels (channels = chat rooms).