It is what Robert Oschler, a Florida-based programmer, did. He bought a Rovio - a Wi-Fi enabled mobile webcam robot that can be picked up from toy sections of many stores - and modified it to suit his needs.
The robot already has a camera, a microphone and speakers, but the improvements he made to the software allowed him to enhance the audio and video quality of this existing equipment, and to create specific routines for the robots. This way, every time he feels the need to check what's going on in the house, he simply goes online with his laptop and directs the robot through the house.
What was once the stuff of science fiction and thought to be accessible only to government and military outfits, has become suddenly available for anyone who is willing to part from a very reasonable amount of money - usually well within the bounds of $1,000. Oschler himself offers his own improved software for the Rovio and other robots on his website, and he offers it for free.
This set up may not be reliable enough for guarding, let's say, a bank, but for the home is well enough. And Oschler is no the only one who experimented with this type of home security. There are plenty of enthusiasts out there who have the knowledge to modify toy robots to suit their needs. According to the Mercury News, a guy from China outfitted his Rovio with fire detection software and a small fire extinguisher.
Peter Redmer, the manager of robocommunity.com, says that members have been known to create software for better aiming the camera and add physical improvements like adding extra lights to improve night visibility.