Wireless camcorder (disturbia)?

Ok i was watching disturbia and kale takes his camcorder and makes it into a wireless security system deal where what he films shows up on a tv screen. I know there are wireless systems out there but is it possible to make that yourself if you have the right stuff?

Radio Shack (and other vendors as well) sell wireless video/audio transmitter/receiver devices. Both the receiver and transmitter are the size of hockey pucks and have flip up disc antennae. You plug the camcorder video signal into the transmitter unit and plug a monitor, VCR, etc. into the receiver, turn everything on and you've turned your camcorder into a wirelessly transmitting camera. The problem with the Radio Shack version is both transmit and receiver units require AC power and do not have battery compartments. The kit is less than $50.00.