[An NES gamepad library for Arduino.][link]
>One use of this is to allow your Arduino access to the status of 8 buttons (up, down, left, right, A, B, START, SELECT) using only 3 digital pins (for STROBE/LATCH, CLOCK, DATA).
3 pins is a tall order on my Arduino Uno, but for the new Due it’s a drop in the bucket. It supposedly works with the [Freedom Stick][freedom], too. Wireless Arduino NES Remote here I come.
[link]: http://code.google.com/p/nespad/ “nespad – NESpad Nintendo game pad library for Arduino – Google Project Hosting”
[freedom]: http://en.wikipedia.org/wiki/Freedom_Stick “Freedom Stick by Camerica”