Does this exist already? and if not would there be any interest in such a thing?
I mean for anyone to be able to advertise an open bet, and when such a bet is placed with another (or multiple others) have the funds placed in escrow until the outcome is known.
I think there is a way to do this without a trusted third party. But only for bets where the outcome is publicly known.
It would work like this:
when the bet is actually placed an encrypted wallet is generated with one half the key going to each of the bettors and one half going to a third party. the third party can't steal coins without the entire key. the only other issue is that they could hold coins hostage. this is solved by building in a time limit such that the original bets revert to their original owners after a certain time has passed. all the third party could do to screw with it is prevent current bets from going through once, after which no one will bother using the service anymore.
this works fine for outcomes that are public/uncontroversial. the third party sends their half of the key to the winner and the winner confirms they got it.
edit: just thought of another issue of the third party colluding with the loser. hmmm. any thoughts?