Ripxx is a waterproof and shockproof gadget that uses three accelerometers and three gyroscopes to record your path speed, vertical drops, spins and falls for playback on your computer later.
It also reports time of run, top acceleration, speed, jump data (time in air, distance, height), rolls (count and rate), top altitude and steepness of runs. The 3D playback of your data is done in third person, over 3D terrain.
You'd figure there would be an app for this already but there's no doubt in my mind that if its good enough for the US bob-sled team, all those sensors and gyroscopes must be good enough for me. [ripxx via Popsci]