I'm not sure that you could do that...
My experience (Motorola i335 containing SiRF GPS of some sort) is that when the phone sits in one
little place on my coffee table it still reports different lat/lon locations.
I see it jumping all around my street - something like 50 yards in every direction. That doesn't cover
when the GPS can't get a satellite fix and it reports the nearby cell tower location.
So... if you sit still it reports different locations. If you're not sitting still... you get a series of different
locations also. Basically, I don't think I could the same location twice in a row with this thing.
It might work for driving and a slow reporting rate. In this situation the expected distance between
locations is much greater than the GPS scatter from sitting still.