We've all encountered them. Those squiggly words that make us prove that we are human. But did you know that odds are when you are deciphering the gibberish, you are lending your services to groups like Google, the Internet Archive and the New York Times?

They are called CAPTCHAs, an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart." You've probably come across them while signing up for an account or digg-ing a page. Well thanks to NOVA Science NOW, a guilty nerdy pleasure of mine, I learned last night that some of these test are actually helping to digitize books.

It is called reCAPTCHA and it is the brain child of Luis von Ahn, a computer science professor at Carnegie Melon who had a hand in developing the original CAPTCHA. Luis had a problem with how much time we waste (5,000 hours everyday according to Luis) by completing the CAPTCHAs, so he came up with a way to put us to work.

The process of  digitizing books in imperfect. Computers have problems deciphering old books. So Luis turned the indecipherable words into CAPTCHAs and suddenly projects like Google Books and the Internet Archive had 5,000 hours worth of free labor.

ReCAPTCHA uses one original CAPTCHA and one of these words from an old book, and assumes that if a person can correctly identify the squiggly text, then they will get the book word right as well. One of the most recent projects reCAPTCHA took on was to digitize the entire archive of the New York Times, and if you've ever worked with microfilm, you know reading those spotty words is no small task. Thanks to reCAPTCHA, the entire 130 years worth of papers should be done by next year. That's teamwork! 

Feeling generous? You can donate your time to digitizing the world library here. Be careful though, reCAPTCHA is addicting. I did 25 words before I could pry myself away. Try imagining you are a monk in a monastery up on a mountain copying old texts. ReCAPTCHA as the new trendy form of meditation... I like it.

(image from  recaptcha.net)