Sherpa has a cute little Torture a Spammer Game. The game play won't hold up to more than 2 or 3 plays, but it's OK the first time round. I particularly like that they are trying to use it to boost the reputation of opt-in mailers (or at least disassociate them from the more nefarious spammers). Oh, and it's funny in a semi-ironic sort of way that they try to get you to sign up for their mail list.