Earlier this year I picked up a Panasonic CS950 pan/tilt/zoom camera. Analogue so not brilliant resolution, but the quality is good for what it is, and the zoom is very impressive. I built a housing out of sewer pipe pieces.

The PTZ is connected into a £15 ethernet/RS485 adapter. I picked up an expensive Pelco video encoder (NET5404-T) off ebay cheaply and they have a free recording system called Digital Sentry which seems pretty reliable, but I think you can hook the encoder into lots of things.

I have added a couple of CS854s into the system too but they are not quite as good quality, but they are much smaller.

I'll post some photos later.