I've been thinking the same for my Galaxy Note - either with a Bluetooth 12v camera, wireless IP camera, or worse case through a wired camera, but they all fail at the Note point.
I'm pretty sure I have seen an RGB to Note adapter cable somewhere, but think this is predominantly designed as an output from the Note to the RGB connected device.
I want to use the Note as the screen for the remote camera, even better if I could have more than one camera (or a moveable camera) for hitching up the caravan or reversing the caravan, when I don't have a spotter with me.
Hopefully someone has some ideas? Thanks.