Summary: <p>Computer scientist Luis von Ahn’s programs harness the human brainpower to solve complex problems. von Ahn invented ReCaptcha, a program that uses squiggly characters that humans easily decipher but blocks spambots – and helps digitize millions of old texts. The <span class="caps">CMU</span> professor also makes games that use human knowledge to improve computers. Find them at gwap.com.</p>
