[Sk3tch] rigged up a way to use an original NES controller with Android. He bought the controller and a breakout board for it at DEFCON. By combining the controller, an Arduino, and a blueSMIRF BlueTooth module the controller can be used as a keyboard on his Android device. In the video after the break he demonstrates pairing the devices and playing Super Mario Bros. 3 in an emulator.
He calls this Alpha quality but it certainly looks like it works well. In the beta version we’d love to see all of the extra electronics inside the controller case like those USB mods.