newegg offers the refurbished TRENDnet 802.11n Wireless Internet Camera, model no. TV-IP110WN, for $29.99 plus $2.99 for shipping. That's tied with our refurb mention from a week ago and $17 under the lowest total price we could find for a new one. It features 640x480 video capture, 3x digital zoom, event notification via email, motion detection, 802.11n wireless, Ethernet connectivity, and more.
A 90-day warranty applies, although it's unclear who backs it.