This was mentioned on another thread as being an interesting project. I haven't created a tutorial as its very easy!http://www.gpsvisualizer.com/
does it all for you.
Make sure you read the help files about building plain text waypoint files, and track files, at http://www.gpsvisualizer.com/tutorials/
Here is a very simple example of a track file containing latitude, longitude, and altitude:-type,latitude,longitude,alt
The first line shows what the column contains and you can add and remove different sorts of data.
So just copy that example into a text file and upload it into 'GPSVisualizer' and there you have it!
One implementation would be to use WebbotLib to store the info in a file on an SD card.
On startup you would write the first line (the column headings).
In your main loop read the GPS and if the robot has moved by a 'significant' distance then write out a new line of data. Also check if the user has pressed a push button and, if so, close the file (to flush it all to disk) and stop your motors.
Then move the SD card to your PC and upload into GPSVisualizer