I got my start with drones by using Lego's Mindstorms robotics platform to fly a plane, creating a Lego UAV (which now hangs in the Lego Museum at the Lego HQ in Billund, Denmark). Back in those days, the only way to connect a GPS was to use a unit with Bluetooth and connect it wirelessly to Mindstorms, which was always a bit of a hassle.
Now there's a new module that allows you to connect a GPS sensor like any other Mindstorms sensor, via a cable. Created by Dexter Industries, it can be programmed in NXT-G, RobotC (my favorite) and Lejos. It costs $105. I've had a beta for a while, and it's a very nicely made bit of gear. I may not put Lego back in the air again, but this is going to be great for ground rovers.
Here's a video of a Mindstorms rover navigating with the GPS module and a compass sensor: