I've been watching the Tour of California stage race (it's on Versus if you get that channel), and was surprised to see a commercial for roadID that was a short bike safety video for regular riders. It's also on youtube, http://www.roadid.com/RoadRules/#TE9UJU_YdUY

Yesterday there was a crazy crash involving 3 riders. The worst & the crazy part was the 3rd guy to go down in a chain reaction. His rear wheel was taken out, spinning the bike instantly around backwards but still upright, & flinging him backwards and headfirst into the pavement with the back of his head - really hard. He looked to be out cold. I was surprised today to learn that he was OK (slighly concussed) and racing again. Another good reason for a helmet.