'Designing out' spam
As the old idiom goes, prevention is always better than a cure.
This holds true more than ever with Spam, and more than ever prevention is definitely possible.
Most spambots available today, even best-of-breed spambots, ‘grow bored’ fairly quickly, that is to say, they hit your site, scan the page for forms, enter their spam and then go away again.
So with a little thought, you can actually design out factors which make your pages more attractive to spambots.
This page will be updated with ideas, examples and links to further articles in this vein.