The Monash Bayesian poker project was started by Kevin Korb in 1993. Since then 5 honours students have worked on various aspects of the project and some of the work has been written up as research publications (papers available online).
Our Bayesian poker player (BPP) was originally developed to play 5-card stud poker, using Bayesian network technology. Most recently, BPP has been converted to play Texas Hold'em Poker, the main online form of poker, and re-written in python. BPP has participated in the world automated poker playing competition at the main American Artificial Intelligence conference AAAI-2006 and AAAI-2007. We have also developed a simple GUI interface that allows people to play against BPP via the internet.
This project offers lots of options for making BPP a better poker player including improving its bluffing strategies and its opponent modelling. Or you might be interested in developing a much more interesting playing interface.