Track down your stolen laptop for free....Use Prey

What is Prey?  It's free software that allows you to remotely monitor your stolen laptop, retrieving screenshots, webcam pictures, and Wi-Fi hotspot information that you (and the police) can use to retrieve your laptop.  There are some steps and advice you will need to catch yourself up on in order to use it properly, for that, check out this article from MaximumPC that gives you step by step instructions on how to effectively use Prey.