PredictionBook is a site to record and track your predictions.
Rather than just recording what you think will happen, PredictionBook allows you to record just how sure you are that it will happen. You can distinguish between those things you think will probably occur, and those things you're really really sure will occur. If you're properly calibrated, you'll be able to see that about 60% of the things you're 60% sure will happen, do happen, and 90% of the things you're 90% sure will happen, do happen.
PredictionBook was originally written by TrikeApps, the geeking arm of the Investling Group, which then merged into its sister company Bellroy. PredictionBook is now an open source project hosted at GitHub.