Check out these guys (Yes, the pink and green hair are wigs) who made a WoW (World of Warcraft) Treadmill.
I remember when WoW first came out, it was cool but took way long to play so I gave up early on it. Well, honestly, I rather hit golf balls than play video games.
(But yes, get me started and I will probably wind up on the top of gamers list and also have to go to Gamerholics Anonymous)
“We bought extremely cheap manual treadmills off of Amazon and decided to sense their speed with a mouse rather than trying to hook into the treadmill’s output with some sort of analog interface. I wrote a quick script in GlovePIE to calculate the maximum speed my mouse could track. It’s a nice MX Revolution, but I could only get it to track a little over 4mph. If we were going to run at 12mph on the treadmill, a mouse wouldn’t be able to keep up. We decided to use a bicycle tire pushed against the treadmill to reduce the speed the mouse would have to track. Eli used a 26” tire and tried to get the sensor about 1.8 inches from the axle so we could make sure to get the full range of speeds. I wrote another script in GlovePIE to convert the mouse speed to “w” pulses. So the faster we ran on the treadmill, the faster and longer the “w” would be pressed.”