The Foresight Exchange is an ideas futures market: http://www.ideosphere.com which is basically a game because it uses play money. Players in the game achieve a high score through their ability to predict the future--claims about future events are traded on a market, and those who predict correctly see their investments rise in value. 

For example, on claim on the market is TheFutureOfITJobs (http://www.ideosphere.com/fx-bin/Claim?claim=ITJOBS) which claims that there will be 35% more IT Jobs in America in 2012 than there were in 2002, despite OffshoreOutsourcing and the like.