Recommendation engine Hunch, launched a Facebook game. Hunch will predict your answer to questions like whether or not you like comic books. The best thing about the game is when you subconsciously lie, answering what you want to be true about yourself, and Hunch comes back with the actual answer.
It's eerily accurate. During beta testing with 30,000 or so users they've seen 83% accuracy for U.S. users and about 75% for non U.S. users. The data, says Hunch CEO Chris Dixon, comes from 400,000 Hunch users who've logged in via Facebook Connect and have answered around ~150 questions each. That's created the Hunch "taste graph" and served as a starting point for their prediction engine.
More Info: Hunch Predic-o-matic