Here is Luis von Ahn, one of the creators of online authentication services Captcha and ReCaptcha. A quirky and entertaining kinda guy with clearly an enormous brain.
In this fantastic 16-minute talk via TED, von Ahn outlines a bit of the history behind the first Captcha, then explains what Re-Captcha is REALLY doing, and then finally talks about DuoLingo, his latest project to allow web users to learn a foreign language in a way that simultaneously helps to translate websites and other documents.
It's worth the viewing time...
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