What's stopping these things from including a heart rate monitor as well? Do we just not have the sensors, or are they just not as cheap as a simple accelerometer? I'd be much more interested in the exercise tracking if it did something besides "steps". Most devices have the same issue as far as I know. If I'm doing an oly lifting workout I don't do very many steps but I sure do a lot of work. I'd love to be able to quantify that.