Bughouse is an interesting type of chess where four players, two per team, play chess on two boards. When one member of a team takes a piece, his partner gets to drop that piece on his own board.

I know a lot of you know this, and I know bughouse chess has been suggested to Fencer.

Maybe we can have a variation on this, where only two opponents play (without teams), yet the players play simultaneously on two boards. The boards can be shown on the same screen. When a piece is taken off of one board, it can be dropped on the other board.