Prey is an anti-theft solution for laptops and mobile phones that lets you keep track of your device and can help you locate it in case it was lost or stolen. The program basically runs as a local server on your system that interacts with an online website, which it frequently checks for a signal that will cause Prey to start uploading its geographical location (via GPS or nearby WiFi spots), IP address, network information, a screenshot of the desktop, and more.
This project has created a free and open source software to track down stolen laptops. I highly recommend you check it out.
it is free, minimalist and does not do anything annoying after installation .
The only downsides will be true of any software based tracking solution it tracks the laptop when it is online and running on the same os (meaning the thieves did not format the hard drive).