A neat idea !

First problem: what sensor technology are you going to use to detect your self ? I have seen commercial systems that use Infra red LEDs in a handheld transmitter and a pair of photodiodes on the camera.

Infra red security sensors probably won't work, because they need movement (change in IR flux) to trigger them. You could I suppose have a little radar tower with one on, being turned continuosly on a stepper motor...

It will detect where the hot blob (sorry) is and turn the camera to face it. The camera and the tower could be separate.

This is much more fun than sorting LCD displays out isn't it ?

Steve