I'm just wondering. The iPad has an accelerometer and compass. So is there an app that can calculate your location based on where your starting point is, what direction youre facing and the accelerometer readings? Something like this: I tell the app I'm at home. I then proceed to take my car out of the driveway. I then turn west. In the meantime, my car accelerates to 25 mph. Because the app knows which way I'm headed, how fast I'm going and where I started it should be able to calculate where I am without a GPS receiver or Internet connection.