Ever heard of Project Honey Pot? No, it's not porn. It's a homebrew distributed system for trapping spammers. Sure, I wrote my own little page for that, but all mine does is attempt to fill spammers' databases with bogus email addresses. Project Honey Pot collects IP info and goes after the spammers.
This week, they're releasing five new features to make it easier to participate, and I've just installed a quicklink, which is their Monday feature. If you've got a blog, as most of my readers seem to have, then check it out.