Slashdot has a pointer to this article on O’ReillyNet by Dru Nelson who talks about Trustic — a service by Mark Fletcher, creator of Bloglines.com. The deal is, Trustic creates blacklists based on feedback from its registered members.
Anyway, this mention is part of a larger discussion about “Defending Your Site Against SPAM” — Part 1 and Part 2. Part 2 discusses implementing protection with qmail and how to incorporate Trustic into your configuration. Very interesting stuff!