Have you ever encountered a CAPTCHA? The test consists of typing in a few random letters in an image and is designed to fight spammers. In fact, if you have ever posted a comment on this newsletter's web site, you have used a CAPTCHA.
Now those CAPTCHAs are being used to transcribe old books that are out of copyright. The system is helping to decipher about one million words every day for Carnegie Mellon University's book archiving project. The system is helping to decipher about one million words every day.
A CAPTCHA (Completely Automated Turing Test To Tell Computers and Humans Apart), is a bit of software designed to keep out automated programs known as "bots." When posting comments on this site or on any of thousands of other web sites, an image containing letters or numbers which have been heavily distorted are displayed. The human is then asked to type those letters. By requiring web site visitors to type in the contents of the CAPTCHA before being allowed in to the site, humans can be admitted while all but the smartest bots are rebuffed.
You can read more about this project at http://news.bbc.co.uk/1/hi/technology/7023627.stm.