I was just on the phone with my brother talking about my recent bike crash and he had a great idea:

Automagic Bike Camera

Imagine a small box (size of a small cell phone) strapped to your handle bars. Inside, it simply contains a small flash, camera(s) and a battery. The camera is triggered be a physical inertia switch – perhaps a ball bearing and magnet. Under normal conditions it uses no energy, but when you crash it triggers a snapshot of the incident.

Would be a handy little black box to record the license of the car that struck you.

Or, simply a photographic memento from that time you ran into a fence while doing single-track on your tall bike in the dark :)