As I mentioned previously, one of my fall-break projects will be a Bayesian spam filter (written in Perl). My initial research starts with Mr. Paul Graham, a major player on the Lisp advocacy front, and bayesian spam guru. Specifically, the basis for my filter will be rooted in the following:
A Plan for Spam
Better Bayesian Filtering
SpamArchive.org

My motivation is two-fold:
1) Strengthen my Perl skillz
2) Create a better filter than the one I’m using (Apple Mail).

If the urge hits you then go ahead and read the articles and send your observations/suggestions along to me.

-m