A modder by the name ZodTTD has modded a Nintendo Wii remote to actually play games on an emulator on a iPhone. The video shows him controlling the game on the iPhone with the D-pad and buttons on the WiiMote.
The mod uses something called BTstack which uses the Bluetooth in the iPhone to use devices that are not supported by the iPhone. In this example, a WiiMote playing a emulator game on the iPhone.
Check out the video after the jump.