Open Source Software for Author Chat

[kevin smith]

Dear Web4libbers,

Southwest Michigan is participating in a one book one community
program.  I have set up an on line discussion group using phpbb.  This
seems to be working fine, however, we are going to have the author
participate in an author chat with students at one of the local high
schools.  The phpbb program has private messaging capabilities but it
isn't really set up for a live chat session.

Can anyone recommend a good chat program that is free, easy to install
and will work for an author chat session?  Our website is hosted
remotely and I have php and mysql, however, I only have access to a
single mysql database, and can't create a  new one.

Thanks,

Kevin Smith
Assistant Director
Cass District Library