In light of the rather impressive Tile Rack app (which will enable players of EA's Scrabble to view their letters on their iPhones, keeping them secret from opponents), we couldn't help thinking about other potential uses for iPhone/iPad connectivity.
In the past, having a sub-device has created some brilliant gaming experiences.
The Dreamcast made early forays with its removable VMU units, which sat in the pad and displayed private player information. Zelda: Four Swords used Game Boys as controllers for games running on the GameCube. And the recently announced Batman: The Brave and the Bold will have Wii-DS interconnectivity.