The Spamhaus Project.

‘Spamhaus tracks the Internet’s worst Spammers, known Spam Gangs and Spam Support Services, and works with ISPs and Law Enforcement Agencies to identify and remove persistent spammers from the Internet.’

Spam afflicted peeps should also check out the ‘Why am I getting all this Spam?’ site, which looks into the ways we can get trapped into a spam deluge, and tips on how to avoid it.