If you are interested in sensors this is the youtube video for you. It talks about accelerometers, magnetometers, gyroscopes and how to use their aggregated data (fusion) to make sense of the movements of objects.
David Sachs began developing motion processing systems as a graduate student at the MIT Media Lab. His research there led him to InvenSense, where he continues this work with MEMS inertial sensors used in products such as the Nintendo Wii Motion Plus. David’s designs incorporate gyroscopes, accelerometers, and compasses in various combinations and contexts including handset user interfaces, image stabilizers, navigation systems, game controllers, novel Braille displays, and musical instruments.