Grouflon has written up a unique project using an Arduino and an NES controller. “This week I worked on little script/manipulation that turns an Arduino and a NES controller into a USB Keyboard. Maybe it can be of use to some of you, so feel free to grab the code on this github repo. This require some simple Arduino modification but the documentation on the github page should cover pretty much everything (if not, don’t hesitate to ask me questions on the comments).”
The code and details are available on GitHub.