There are not expletives strong enough. In a nutshell: it's a pyramid scheme for following people you don't know on Twitter. It asks for your username and password. Terrifying.

"The dataspace of the well-tempered environment will soon be invaded by logos, credits, banners and offers. The financial temptations will, I suspect, be too hard to resist." Loads of excellent stuff in here besides this, though. Can't recommend enough.

Someone beat me to the punch - takes a different tack to my acts_as_akismet, but definitely worth a look.

Mail.app's spam protection isn't so hot these days. Perhaps this is the answer?

Distributed spam-catching system. Built for Wordpress, but works with anything. Will be putting this to use soon...

Ruby class for checking spam against the Akismet distributed spam-processing service. Could be useful