I just came across Adeona which allows you to track misplaced or stolen laptops without having to rely on third party providers. I think this make a lot of sense – you can have encrypted drives etc, but if you can also have your machine call home, that would make things all the more useful.
While I do not intend on loosing my laptops, I am wondering if there are other purposes this GPLed code can be used for? Ocassional call home with status check, discover nearby systems etc. Food for thought.