Chat program - need some resources

Hi there. Can you give me a web site that has good resources on making a chat program? Specifically, I''m looking for conversational AI, so this does not necessarily have to pertain solely to chat programs. If you''ve read the article "group conversations" in the Game Design forum, you''ll know what I mean. My goal is to make a simulated chat partner that acts more like a human than any other chat programs I''ve seen (which amounts to those old BBS chat progs). Any help is appreciated. I hope to apply this technology to an RPG someday, and I''d be happy to share my results with other developers later. Thanks.