I am trying to get my wife to buy me one of those car navigation GPS units tomorrow. They are normally around $250, but are going for around $129 at most stores. I'm specifically looking at the Tom Tom One 3rd edition. I know how they help you get places, but my question is, if I am at a new location (for instance I end up at a good fishing hole and don't really know how I got there), will this type of system allow me to calculate the GPS coordinates? I can't seem to find it on the specifications anywhere. Thanks in advance.