I had no doubts that some forumers would shares similar interests regarding geography and maps. I was always good for naming countries on maps and cities around the world, even though I can't say I developed an "expertise" on streets or neighbourhoods like you guys.
Apparently no forumer is crazy enough to carry a GPS in his car or when walking around cities though.
The one thing that doesn't help is if the GPS technology allowing to upload your tracks on Google Earth arrived after you have had traveled around North America or the world for years, or even decades. I see that someone in this situation wouldn't see any use to buy a GPS for this purpose, since 99% of his exploration wouldn't appear on Google Earth.
In my case a good chunk of my urban exploration and travel was done after I bought my GPS a couple of years ago, so it does represent pretty well the places I have been too (at least in North America).