Front Door Video Camera
If your front door has one of the peep hole viewers, you can use this method to mount a small video camera in its place.
A small project box outside contains the video camera ($25 from Circuit Specialists). The camera is hard to see in this picture; it is in the top half of the box. A hole just below the center is fitted with a short piece of lamp threaded rod (from your local hardware store), a big washer, and the matching nut. The metal cover for the box is replaced by some 0.060 lexan and held with 4 screws.
The other side of the door (rollover image) has a small plastic electrical box with another washer and nut. Wires from the camera run thru the threaded rod and terminate in connectors on the side of the box.