So the $8 GPS Neo-6M sensor I bought and plan to start playing with tonight for my next project is accurate in providing your location within 2 meters or 6.5 feet. They also make a fair bit more expensive Precise Point Positioning (PPP) version that can locate your location often down to a few centimeters.

Back when Albert Eisenstein released his theory of relativity, I bet he would have never realized that he had found the answer to one of man’s great problems — where am I? It’s been less then 20 years since consumer GPS has even been a thing.