I have one off ebay it works great, Nanny spy cam or something like that. It works well at slow speeds it can't take much shock though. I can put it in my clod buster and drive the truck outside in the heat. By watching the TV inside the air conditioned home.
I am thinking about rigging up a system for a handicapped man at the local r/c rock crawling comp. Being that he is in a wheelchair he can't see his truck when it's up high on the rock hills. It would end the, "Turn your wheel to the right and back up", "Ok I can't see it though"
Here is someone's sample footage, after seeing this video I knew I had to have one.
http://www.badgerracing.com/~rcracer...light=wireless