So, you've got yourself an accelerometer...
1. Who walked off with my XXXX?
2. Handheld XYZ gadget's screen is facing down on the table. Turn off what cannot be seen.
3. My car is housed in a long time parking facility (I'm out of the country for a few months). Who moved it, and when?
4. Can't acquire GPS (or Comm Satellite) with a patch antenna when the patch isn't oriented correctly. Why waste the power?
5. No. Nobody simply bumped into or moved my bike out of the way. Ack! Somebody is riding away with it!
6. Out on a nice hike. Oops, I've fallen down the slope and can't get up... or.. OH MY GOD: I'm being thrashed about by a bear.
Okay, so #6 is a bit far fetched....