I tried taking a pic of my speedo once on a track. Just as I got to the pointing the camera in the right place bit I hit the speed limiter. I thought I'd blown the engine and paniced a bit. End resut was that I dropped the camera as I grabbed the wheel with both hands expecting to fly off the track at 155mph! A more entertaining shot would have been the state of my underwear afterwards!
I'd never do it on the road. I don't care if I kill myself but what about those around me?!
WK