And these, which are all over eBay (search for "808 camera", this is just the first google hit I got, not any particular recommendation for this seller):

http://cgi.ebay.com/808-Car-Keys-Micro-camera-Spy-DVR-Suppor...

and _really_ inexpensive - you get ~60-70 mins of recording on a 4gig card, which is about the internal battery life too. I bough a few of them and am playing with recording my 40min (motorcycle) commute every day...

Again, they miss some of the stated requirements, but at $15 or so they can be forgiven some faults...