Interesting thought about the videos, OLEOSTRUT. A lot of phones also have accelerometers and gyroscopes in them these days. Not good enough for an INS app yet, but it's in your future. One of the reasons they are inaccurate is because of slow refresh rates, but if you had several of them, maybe the data could be integrated.
http://www.mouser.com/applications/s...olutions_mems/