I've installed Prey onto my Dell Mini 9. I'm considering also installing it onto my wife's Dell Mini 10 and both of our Macbooks.
Prey is a small and free application that will help you track down your machine if it is stolen. They've agents for Windows, Mac OS X, and Linux. It can be run on a desktop or laptop.
What you do is register with the website, install the application onto the machines you want to monitor (up to three per account). You then sync keys between the application and server software. You can monitor many things on the remote machine from the Prey website and can determine the general location of your equipment. You can even send messages to the thief!
This software gives you the chance to recover your equipment by enabling manipulation of the system. It can alert the 'new owner', it can be tracked via traceroute or GPS, the logs and processes can be monitored, and the webcam can be enabled.