I've tried this thing (Score 2, Informative)

The manufactuer had a booth at the Seattle Bike Show last weekend with a demo "box" - basically a video screen showing the road and a helmet with the HUD system attached. The result is very neat: the thing is so close to your vision that your eyes pick up the information and display it "over" your normal field of vision. Within a few seconds, I wasn't looking "at" the information but at the "road" of the video. I could still see what gear, rpm and speed was being projected without refocusing. That being said, I didn't care for it: It is an external mounted display that I know I would lose or damage. If helmets came with the system built in, I would consider it, but...

- Erston