The local news station ran a story about a guy who had his MacBook stolen. He went to the police, who of course were no help. He had installed tracking software called Hidden on his Mac. This software, like others, will allow you to track your PC or Mac's location, and also take photos remotely -- showing the person who is using your stolen Mac.
He went to the police with photos of the suspect, along with the exact location of his laptop -- and they finally got his computer back for him.
I myself have been using the product undercover for my Macs for several years now. It provides basic tracking information, and a new feature takes photos. I believe it is only for the Mac, and it costs a flat $45 for five Macs. There is no annual or recurring charge.
Hidden costs something like $15 per computer per year.
I recently discovered Prey for Macs and PCs, as well as Android. It is a free open-source software that provides the same capabilities that I describe above, and more. I will likely be installing this on my computers in the future.