Hearts?  That would be pretty cool but what would be even better would be able to play rubber bridge and play it for Bitcoins!

Did a quick Google search and did not find it.  That is a fantastic idea for all of us who love to play bridge for money.

You have to handle the collusion problem but that has already been solved by the other bridge for money sites on the Internet.  One site does this by randomizing partners on every hand.  Another site pits one human player with a bridge robot partner against a second human player with a bridge robot partner.