Prey is a great way to recover your laptop or phone if it is stolen. If your laptop is stolen and you have have signed up to Prey you can track your computer with the help of Google Maps.
Prey uses either your device's GPS or the nearest WiFi hotspots to triangulate and grab a fix on its location. It can then show you the location of your stolen property on a Google Map. All you have to do then is report the thief's address to the police and await the return of your computer.
Prey also comes with some other handy features, such as being able to take a photo of the thief with your laptop's webcam or being able to take a screenshot remotely (perhaps catching the thief's name whilst they are on online).
Storify has a really interesting account of how someone managed to recover their stolen laptop with the help of Prey and some Twitter friends.