Anybody know of any cheap, hackable treadmills?

Hello, I was wondering if anyone knew of any cheap and hackable treadmills. I saw a website about that and it got me thinking that games that involved just walking on a treadmill could be really cool. It could be a little dangerous, but I guess the DK2 camera could tell you if you were about to fall off and also stop the treadmill if it was hacked enough to control the speed and stuff. Oculus Rift + Control VR + treadmill could offer some really great gaming opportunities. Games where you are pretty much just walking forward the whole time.

http://electronics.stackexchange.com/questions/79451/hacking-a-treadmill-with-arduino

I guess this would be better in the input devices forum, my bad.