For the case of buyer-seller disputes, Bitcoin has a really neat way of handling escrow with its m-of-n transactions [1]. You can make a payment that requires 2 of 3 public keys (the 3 keys being the buyer's, the seller's, and a trusted third party) to be redeemed. If the buyer/seller agree, they can move the money on their own. If they don't, they can go the the third party and solve it with them. Yet, the third party never controls the money and can't take it without one of the buyer/seller signing the transaction. Indeed, all is needed is some trusted company to start doing that.