Check the full article for details on options for other device types
Say your laptop has turned up missing. If it’s loaded with PC-Trak, and somebody turns it on and connects it to the Internet, you’ll have a fighting chance of getting it back. The PC-Trak software loads up automatically when the machine is booted, and sends a ping over the Internet to the main GadgetTrak server. But nothing happens unless you’ve notified the company that you’ve lost your laptop. In that case, PC-Trak swings into action.
The program uses software developed by Skyhook Wireless Inc. of Boston to identify the laptop’s location to within about 100 feet. Most laptops don’t have built-in GPS chips for precise tracking, but Skyhook has created its own Wi-Fi profile of the nation by mapping thousands of wireless hotspots all over the United States. As soon as your laptop picks up a couple of nearby Wi-Fi routers, it’ll tell you where it is.