This Christmas you can choose between two roaming sentinel robots featuring camera and wi-fi connectivity. The WowWee Rovio ($239.99) challenges the Erector Spykee ($247.65), which was supposed to be available a year ago, but was delayed.
A robot fan with a hand for video named Sven literally made a Rovia versus Spykee video letting the two robots go at it each other in a "box ring". See the video below.

Robotsrule has a more technical comparison between the Rovio and the Spykee. The toy robot site prefers the WowWee Rovio: "Watching Rovio monitor the ceiling for the Northstar navigation beams and make small precise alignments while backing in to its charging deck is a breathtaking science fiction moment. WowWee has also done a great job in providing support with router/hub/WiFi configuration issues and the web interface is terrific. For home or office surveillance there is no other choice".

The Erector Spykee sells for $247.65 on Amazon.com.
The WoWee Rovio sells for only $239.99 right now on Amazon.com.