We love finding out how things work, and arguably one of the most important parts of the smartphones and tablets we thrive on is the accelerometer gauging our device's orientation. Imagine our delight, then, when we see the University of Illinois' Bill Hammack (i.e. The Engineer Guy) giving a visual rundown of how accelerometers work. Although it's certainly the Cliff's Notes version of what's going on in your Android phone or iPhone, the video does a great job of explaining the basic concepts behind three-axis motion sensing and goes on to illustrate how MEMS chips boil the idea down to the silicon form that's needed for our mobile hardware.