http://www.bbc.co.uk/news/magazine-18367017 - original article. Every time you type in a captcha you could be helping to digitize a whole series of different books - the aim is that every book in the world will become digitized. Typing each Captcha takes about 10 seconds, he (creator of captcha) estimates. Multiply that by 200 million, and humanity as a whole is wasting about 500,000 hours on these security codes every day. He decided to put these hours to good use and devised ReCaptcha, a system that uses each human-typed response as both a security check and a means to digitise books one word at a time. At the same time the New York Times was digitising 156 years of its archive using a team of typists. Over a decade, the typists had transcribed 27 years of newspapers. The paper began using von Ahn's software and in 24 months had transcribed the remaining 129 years of archived newspapers. ReCaptcha was acquired by Google in 2009, and it is still used widely to tell humans and spamming programmes apart. But its translating software is exclusively available to Google's Books project to transcribe every book in the world. So next time you're getting fed up with captchas maybe think back to this - you could be doing some good! Thought it was interesting, hope you did too!