My first intro to GPS units was about 10 years ago, when I first met my wife. My father-in-law works for the Forest Service as a Surveyor, and frequently uses a seriously high end model. From what I remember, he can get within INCHES for accuracy. I thought that was the coolest thing in the world. I use to go out and find benchmarks too. Then a couple years ago I heard about caching, and now I was finally able to afford a unit of my own. Now I'm a cache machine!