ipod touch
There are several free iPhone-iPod Touch apps that let you look at the acceleration of the device using the built in accelerometer.  I was planning on reviewing some of these free apps, but I didn't.  When I started playing around with them, it was clear that I needed some way to make a constant acceleration.  There are two simple ways to do this - drop it, or spin it in a circle.  I decided to go with the circular motion option because I like my iPod and because Steve Jobs told me to.
While playing with this, I realized that the acceleration depends on the distance of the sensor from the…