The iPad and iPad 2 3G models have built-in assisted GPS that support navigation apps and show your location in apps like Google Maps. If you have a WiFi-only iPad model, it does not have GPS, so you might think you are out of luck with getting accurate location information on your device. It turns out that if you have an iPhone 4 running iOS 4.3 and use it’s Personal Hotspot feature, your iPad can obtain GPS coordinates from the phone.
Zachary Bir wrote on his blog that he discovered the capability by experimenting with his iPad connected via WiFi to an iPhone 4. Normally when you run Google Maps on a WiFi-only iPad your location is indicated by a blue dot within a large blue shaded circle. The dot actually represents a network location and your location is determined to be somewhere within the shaded circle. In short, without GPS the iPad cannot accurately determine your location.
Bir found that when he ran Google Maps on his iPad while connected to a iPhone using WiFi and Personal Hotspot, his location was shown as just a blue dot, indicating a more precise location. He tried using the set up while riding in a car, as has another iPad owner who recorded the experienced in a video, and found that the dot moved along on the map as the car moved and the location was fairly accurate. There does appear to be a bit of a lag in transfering the GPS info from the phone to the iPad, but I think the fact that the phone even transfers the info to be an interesting use of the Personal Hotspot feature.