I just read the Wikipedia article on Prediction Markets, and thought others might find it interesting.

Basically, people can be betting monopoly money or only pennies, and they will make significantly better predictions than if you just ask them to guess. Some will use tools like Applies Information Economics to make surprisingly accurate predictions, at least on average. Others will still just guess, but they'll have a calibrated probability assessment, or perhaps will just be playing the game for the sake of better calibrating their probability assessments.

At some point, I need to calibrate my probability assessments, and put all this LW theory into practice.