Spam Filtering's Last Stand
Note: If you're arriving from one of the many links who think I'm underestimating the power of personalization, please see my rebuttal (now with a working link!). Personalization won't work either, and it's nowhere near as powerful as people seem to think.
Recently, a relatively new idea for filtering spam has surfaced: Bayesian classification of e-mail, or at least Bayesian-inspired analysis. This seems to have been recently been brought to the Internet community's attention by Paul Graham in his essay A Plan for Spam, though I know he's not the first to think of it: For instance, here's a programming assignment given at the University of California, Irvine's Information and Computer Science department in Dec. 1999. That the idea was not popular until recently is probably a direct consequence of the fact that since 1999, the war on e-mail spam has been victory Spammers at every turn. The need for bigger guns is now more acutely felt then in 1999.