dlature at Movable Theoblogical is having spam problems. Me, too, and I’ve found that WordPress’s mass comment editing — while a clean-up solution rather than a preventative — has served me better than Blacklist did when I ran MovableType.
Be there was also a question on that entry about obscuring email addresses. I use to use — and ought to use — a nice like bit of javascript if found at the British Unitarian and Free Christian site. And y’all should use it, too.