Why: To patrol your home while you're away, capturing images you can access on any Web-connected device.

The Gear: Tablet PC, webcam, cable, battery pack, strong Velcro

How: Use the onboard PC to send the Roomba instructions to (roughly) follow a predetermined path around your pad. Set the webcam to snap a picture every few minutes and automatically upload it over your Wi-Fi network to a photo-sharing site such as Flickr, which you can log onto from anywhere. Advanced trick: Wire the battery pack to recharge when the Roomba hits the base station so that it can operate indefinitely.