Just picked up a Gamercize to help me get in better shape. The company makes versions for xbox 360 and PS3, but there are no north american outlets for them. However, it turns out they are all exactly the same except for the controller they come with, so the PC version works fine with PS3 an xbox 360 as well as PC.
Basically it makes you exercise or you can't use your controller. If I only let myself play videogames while using it (which, at the least, is as much exercise as walking) it should be good. Since I loose track of hours playing games anyway the time input shouldn't be an issue... and some games are actually MORE fun when you are tired after playing a level. (Altair running across a city in Assasins Creed, for example).