Rigged an exercise bike up to an old Super Nintendo controller using An Arduino microcontroller, some sensors/switches and some transistors.
Peddling at a certain rate holds down the A button to accelerate, left and right are buttons on the handlebars and there is a red button in the middle of the handlebars for using special items.
I have another video I'll upload soon which better describes the bike controller.
There is a quick overview of how it works here:
http://statuswoe.blogspot.ca/2012/04/super-mario-kart-cycle.html including a link to the github project where my very quickly written android sketch is available. I'm hoping to put up schematics of both the bike and SNES Adapter (part of which actually uses an SNES controller) there when I get the chance.
For anyone interested in seeing it work with a non-SNES game Mike McGraw and I came up with a game/adapter that is played on a Computer via USB. I think the game is pretty neat.
Check out the detailed description of how khdownes1 made this (as well as other video game related projects) here: http://ultra-awesome.blogspot.com/
"A while ago I decided I was running out of room for many many videogames and their boxes etc. (I'm one of those fanatics who insists on having everything with original boxes).
So I built this, to replace my current coffee table, it has space inside it to store game boxes etc.
Made from MDF and painted with a variety of oil based and acrylic paints. "
khdownes1 from YouTube