A suggestion for the site (or perhaps the Wiki): It would be useful to have a central registry for bets placed by the posters. The purpose is threefold:

• Aid the memory of posters, who might accumulate quite a few bets as time passes.
• Form a record of who has won and lost bets, helping us calibrate our confidences.
• Formalise the practice of saying "I'll take a bet on that", prodding us to take care when posting predictions with probabilities attached. The intention here is to overcome akrasia in the form of throwing out a number and thus signalling our rationality; numbers are important and should be well considered when we use them at all.