Loïc d'Anterroches by the way has implemented a PHP Naive Bayesian Filter that I could imagine would help me out the most with the trackback spam.
By the way, the script by Loïc did work right out of the box. ;)
Looks cool. Simple API, and also did work for me out of the box. Maybe something for the BxCMS blog.
Beware, the site is in French, and I'm for once glad I at least understand a little bit of that strange language ;)
Update: You can find the English translation of the article on Vidar Hokstad's random musings. Thanks for that.