I had been most of the way through a raspberry pi powered motion webcam before christmas, then made a string of mistakes involving a piss-poor card reader and lost all my work.
The good news is, rebuilding is going quickly. The new Raspbian image has GPIO, Python and now(!) limited support for hardware MJPEG decoding, which gets me closer to a feature I couldn’t implement before.
Current steps –
 Find another dlink webcam to test on
 Configure Motion to trigger a python script upon detection
 Write the Motion trigger script and timer script to keep track of the amount of motion. Should really figure out a collision free way to do this, but my last dueling python method worked…
 Mount my lights in the RasPi case for output through GPIO