The most of your guys know Android can be a phone, but it can be a pedometer too. There is an apps, calls "Pedometer" in the Android Market for this purpose. I think it used the accelerometer in the phone to sense the motion.

I used that to track the calories I burned when I walked from my office to Brisbane City(I am driving to work every day now.). I am not sure the accuracy of this apps, at least it can give me a rough ideal about the amount of engry I burned.