Here is a video of a treadmill which plugs into your computer and records the treadmill movement as forward movement in video games. This one is called Gamerunner and you run on the treadmill and then use a bike handle type device which is mounted on the front of the treadmill to move and fire. I have a similar product called a SimCycle which doesn't work very good for various reasons. The problems with the SimCycle were that it wasn't a real tension flywheel, your knees were always hitting the desk, and you would be winded but you couldn't stop (specifically in racing games) because if you did you'd lose the game. I'd say the Gamerunner is probably a better product then the SimCycle because you're standing up instead of sitting and you can hang on to the bike controller. Still the problem of getting winded though.

There is a review of the Gamerunner here and you can watch the video of the Gamerunner in action below or view it on the host site.

Source: Slashdot