Our hosts at Tricycle Developments have created PredictionBook.com, which lets you make predictions and then track your calibration - see whether things you assigned a 70% probability happen 7 times out of 10.
The major challenge with a tool like this is (a) coming up with good short-term predictions to track (b) maintaining your will to keep on tracking yourself even if the results are discouraging, as they probably will be.
I think the main motivation to actually use it, would be rationalists challenging each other to put a prediction on the record and track the results - I'm going to try to remember to do this the next time Michael Vassar says "X%" and I assign a different probability. (Vassar would have won quite a few points for his superior predictions of Singularity Summit 2009 attendance - I was pessimistic, Vassar was accurate.)
Hi. Who do I go to to request that PredictionBook have an option not to see other people's estimates before adding your estimate to someone else's prediction? I'm anchoring on other people's estimates and it's preventing me from using the site to calibrate myself without generating a lot of my own predictions.
You'd go to the PredictionBook GitHub repo to open a bug report; but PB is mostly in maintenance mode, so unless you're a Ruby programmer...