Having spent a sizable share of the past few weeks writing and supporting an anti-spam plugin for WordPress, I have been extensively reading and cogitating on the issue.
While I am ashamed to say that I have not come up with any magic answer to the problem (and don’t think anybody ever will), I nonetheless have lots of remarks and ideas I’d love to share. And given the appallingly low level of certain discussions on spam I have read lately, I figure it couldn’t hurt.