Wireless Internet camera with motion detection. Streams MPEG-4 and MJPEG video at up to 640x480. Cheapest on StaticIce is around $185.
The difference between this type of camera and a webcam is it's self-contained with its own little built-in web server - it doesn't need a host computer. You can plug it directly into your broadband router and access it from your local network or the Internet.
Spotted this deal a few days and almost picked one up myself, but was reluctant to post because cheap IP cameras often have reliability issues and annoyances. But short of spending $300-500 for an Axis, you probably won't find a better one, and if it works well for you it's a bargain :)
(Edited by scotty — change link)
Got one of these a week ago from OW. It's excellent, sits there and just works. Motion detection, auto recording, emails you alerts, it's awesome and a very good price.