Assuming you were willing to pay to run a GPS tracking system, where would you hope to install it on the laptop? Any scumm of the earth thief who steals your laptop is going to notice a GPS receiver stuck to it isn't he. Either he's going to disable it and end up making off with a laptop AND a GPS receiver, or he'll simply remove it and throw it away, so that the best your tracking efforts will do is lead you to a bin.
I'd recommend getting home contents insurance or upgrading your existing insurance. Mine covers me for equipment on my person up to the value of £2000, which is more than enough to cover for a stolen laptop. Not sure if it covers me for abroad though, so make sure you check that with the insurance company when you make enquiries.
Brian