Edit by wmtire: I moved this post from the "made a wireless backup camera cheaply"
thread and into it's own thread as it has a lot of potential that deserves it's own thread.
I have been following this thread for a short time, While trying to decide which solution, I liked best, I realized I have a great solution already. Just tried it out and works great. I have a WiFi enabled GoPro camera which connects via wireless to my cell phone and tablet. I added one of the quick connect mounts to the bumper. I do not plan to leave the camera on the trailer permanently, but quickly attach it when I need it. Great quality and uses things I already have.