When riding, a camera phone will do. There's the beauty of the place you are riding through. Then there's self defense.
You have a nice day too, Sir.:
"Knowing him, had this guy stopped and been even slightly apologetic, there probably wouldn't even have been a police report. But instead, the driver chose to turn it into a felony hit and run, with three witnesses, a paramedic report, and a photo of his license plate."