from Mashable = 3 iPods and Magic - Magician Separates Lies and Truth with 3 iPods = fantastic video and I just can't figure out how he does it....and probably don't want to know and destroy the mystery.
I read about this and then was able to test it. Was in the car on I-80 [not the driver!] and was using my iPad's 3G connection to check news, mail etc. I had purchased the $15-30 day data plan and had used about half of it and still have some days to go. I also went to Maps and looked up the route to where we were going, found it and then turned off the 3G to conserve the data use. Then, lo and behold, I saw the little blue dot [where we were located on the map] move. That's because the GPS capability [evidently only available with a WiFi-3G iPad] is independent of both the WiFi and 3G. The GPS works whether or not you're connected to the internet. Which makes sense because it's based on a separate technology and system.