Planes have black boxes to record the vitals of an incident. About time cars had something similar, no? Enter the Car DVR, your fool-proof way to put the blame on the other guy. Assuming, you know, it's his fault.
The Car DVR, from China records twenty minute segments of 640x480 video on an onboard SD card, to give you a constantly updated log of what's been going on in front of or behind you. And its motion detector ensures that you only grab footage when you're actively driving—although that also means you can't use it to grab the licence plate of a hit and run on your parked jalopy.