...and I will extrapolate the Earth!
I've been having to estimate the elevation of a bunch of little dams for a project I'm working on, and to do this I am extrapolating the water level and the toe of the dam from between 40-foot contours on an old topo map. Basically it's an educated guess. But I've been getting about 3 feet within the GPS readings we have for the few dams we have GPS readings for, which is pretty much within the margin of accuracy the GPS can give. Upon seeing this, my boss exclaimed: "Why do I have a GPS when I have you?"
It's good to be loved.