Newegg offers the refurbished TRENDnet SecurView 802.11n Wireless Internet Camera, model no. TV-IP110WN, for $19.99. Apply coupon code "MASTERPASS10" and checkout via MasterPass to cut it to $17.99. With $2.99 for shipping, that's $91 below the lowest total price we could find for a new camera. It features 640x480 resolution, 802.11n WiFi, Ethernet, and 3x digital zoom. Deal ends June 15.
A 90-day warranty applies, but it's unclear who backs it.