Well thats a good idea
This is a neat idea that has an implementation and is used on the net: http://recaptcha.net/
To prevent bots from spamming websites most website owners have this thing called a “captcha”. This requires a human to read a graphic and product two words. This is somewhat hard for machines and easy for humans (in most cases). This site actually picks up on the words from digitizing books that the machines can’t read and asks the humans to decipher them. So by using sites with this Captcha we’re helping digitize books and also prevent spammers. And as a byproduct helping spammers help people digitize books.
