Article in Automatiseringgids on [http://www.cs.cmu.edu/~biglou/ Luis von Ahn]’s [http://www.espgame.org/ ESP Game]—a.k.a. the [http://images.google.com/imagelabeler/ Google Image Labeler]—to smart tag images by human swarms.
Ahn also created the spam-avoiding [http://www.captcha.net/news/ai.html Captcha].
Thank you very much Luis!