[jfoutz]

When the MacBook got the acceleration sensor, I hacked up a little program to estimate velocity, and a button to reset at stoplights. Some friends drove me around, it worked poorly. it did pretty ok on the highway, but awful in the city.

I think if I kept messing with it, it'd get a lot better, but I sorta lost interest. This was more of a fun weekend toy.

I think all phones have them, and they might be reachable through chrome/safari. And it is kinda fun to play with, but you'll probably hit sampling rate errors pretty quick. you gotta guess the shape of the curve between datapoints.