Manifold's tournaments seem to organise people well around predicting probabilities related to an event, and it seems like it should be possible to just set those up - e.g. I might want to put M$10000 up for the top bettors in the 2023 NZ general election group, paid out a couple of weeks after the election. (That's not a random hypothetical, by the way!) Any currency would resolve YES, including M$.