Ever since playing through Half-Life 2, I've wanted to implement the automatic security cameras they have in the game.
The idea is to set up a pan & tilt camara mount, with a high-quality flash camera co-axial with a low-light/IR webcam. The webcam is plugged into motion/feature recognition software, and controls the pan/tilt, keeping the largest moving object in the middle of the frame. Once a certain threshold for size/movement is reached, a buzzer and red light activate, and the camera takes 3 or 4 flash pictures in rapid succession.
Anyone who's played HL2 can attest to the strong sense of Big Brother that these cameras evoke. Not to mention the fact that it would produce superior images, as it would wait until the target is sufficiently large in the frame, and the light/buzzer should cause the target to reflexively look towards the camera to investigate.
Thoughts? It's not so much a practical solution to the original stated problem, but maybe a fun project for someone with more mechanical skill and free time than I have...