This video presents the latest iteration of IDSC's Flying Machine Arena failsafe algorithm (previous post here). In this video there's a pilot flying the quadrocopter while the algorithm is executed on the quadrocopter's onboard micro-controller. The only sensors required are the quadrocopter's angular rate gyroscopes.
You can read more on the description of the video ( http://www.youtube.com/watch?v=ek0FrCaogcs )
You can read an older article about the failsafe algorithm mentioned above with more details and photos here:
(take a look at the comments below!)
(video link via M.Waibel)