Return of the CAPTCHA rant

A while ago I ranted about those annoying online tests you have to take in order move around the web (type in the phrase you see). Since then, I've learned they have a name: Captcha (Thanks, Kevin!), which apparently stands for "Completely Automated Public Turing test to tell Computers and Humans Apart". And yes, there's a patent. Apparently I'm not alone - there's a particularly heinous example blogged by Seth Godin. How many collective hours have we humans wasted taking CAPTCHA's? (Computer Automated Process To Consume Human Awareness). Why not take scanned images, say from Project Gutenberg, and let people do the matching on that? Then at the end of it, at least we've created some value. (Insert witty comment about a million monkeys and Shakespeare - nah, too trite.) Oh yeah - that wouldn't prove to the computer that we're actually humans. It seems only wasting our time will do that.