Quite awhile ago I got intrigued by Phil Torrone's Geek Gym and his goal to do 10 miles in 10 cities and then make an art project of the GPS Waypoints he got. I never did see the result of this project, but the idea of mixing the Physical with the Technological/Electrical to produce the Artistic(al) really got me excited.
I wonder what you can do on a larger scale. Running around a park seems like an "intro level" Cartozoology. An intermediate would be plotting it out on streets and then traveling it (and dealing with possible lost line of sight to the pies in the sky). Now a really advanced one would be on the scale of a state or across a country. Even cheat the Etch-a-Sketch and intentionally lost gps coverage to "lift the pen" as it were.
Now if you could upload this to a server *as you were doing it*, people could be viewers of a live drawing project.