Oh, great. Now I get Trackback scatological spam. Cartoon rape sites seem to be heavily promoted. Who likes these? blech. Can some astute programmer write a script that destroys the computers of blog spammers?
Anyway, Six Apart has some tips that I'm about to implement....
Six Apart Guide to Combatting Comment Spam:
This document describes how malicious or unwanted comments ('comment spam') affect weblogs, the techniques spammers use to abuse weblogs, and the tactics that can be used to prevent and defend against these attacks.