Utilizing the deviceorientation JavaScript API for fun & profit (minus the profit)
This is a demo / proof of concept that I put together in about 5 hours. Try this out if you have a device with an Accelerometer and a browser that supports the device orientation API. I'm not sure what will work and what won't... i've tested this on my MacBook Pro running in Chrome, but it should also work in the latest version of FireFox (maybe?)
http://mediaupstream.com/sandbox/level/
MIT License, the world is your oyster.