iPhone GamePad: External controller for iPhone & iPod Touch?

http://www.youtube.com/watch?v=SkB9vQDY3eU&feature=player_embedded

Hello iPhone user, with the large number of emulators available for our device, it's quite annoying that playing in landscape or full-screen mode is so awkward with the emulator controls taking up a large part of the screen. Therefore, this would be a good idea… an external adaptive controller that would improve gameplay.

So far it's just a prototype; it's not known for sure if it's possible, but it would be a great improvement for devices in terms of emulators.