"Spam-Free at Last: For approximately a month now I have been completely spam-free. This amazing feat is the result of a one-time cost of many hours of careful mailbox combing, email address rediscovery, a judicious use of dual-sided addresses for posting and receiving on mailing lists, and a kind of soul-cleansing I never really thought was possible."

The author describes his method at length in this article. His method seems to require a fair amount of work, but there are some other useful suggestions in the accompanying comments thread.