I had one that I played with for a while - it was a total cheapo, came from the dollar bin at Target or something. basically just a balanced weighted lever arm so when you jostle it, it swings enough to tap a switch and it counts. Anyway, I found that if I was going someplace, it counted reasonably well, but if I was just wandering, it hardly counted at all. i.e. standing up in the lab all day and picking things up from one side of the room and going around both sides of the table back and forth all day, and it said I went about 20 steps. I must not bounce enough. I tried clipping it to my shoe, but then it started double-counting things if I got too energetic. It was mostly for the novelty of playing with a pedometer. Pretty cool though!