You need more than a GPS receiver, but a transmitter that sends the location somewhere.
There are systems that send this information via a cell network, but there are fees associated with it, usually monthly.
There is also a LoJack for laptops that tracks location when the laptop connects to the internet. If that never happens and they can't recover your laptop within a certain timeframe, it will wipe your data and they will reimburse you an amount to offset the cost of the replacement.
This is NOT GPS based. It uses IP addresses to determine location.
I don't think any GPS-based tracking module is going to be small enough to be hidden inside the laptop, though.