Alice Chess, anyone? I have read about it at British Chess Variants Society, and the work of David Pritchard. It can be accessed at ChessVariants to see about it. Ed Friedlander has a simple PixelPusher program where you can practice it, if the mood strikes.
It plays as standard chess, but two boards are used, and when you make a move on one board, the activated piece moves to the other board.
(Cacher) Si vous souhaitez saluer quelqu'un dans sa langue natale, essayez notre Dictionnaire du Joueur, par le lien "au sujet des langues" sous les drapeaux. (pauloaguia) (Montrer toutes les astuces)