Here's something worth trying.
Prey is a free and open source laptop tracker for Mac, Windows, Linux (and Android) that will help you locate a lost or stolen laptop or phone by sending you location information.
According to the preproject website, the Prey app will send you "the general status of the computer, a list of running programs and active connections, fully-detailed network and wifi information, a screenshot of the running desktop and -- in case your laptop has an integrated webcam -- a picture of the thief."
Two new features include a module called "Secure" that allows you to remotely remove any stored passwords and hide your profile data from Outlook and Thunderbird and a module called "Lock" that lets you prevent your computer from being used unless a password is entered.
For more information on how Prey works and to download the installer, go to http://preyproject.com