In the Palm Pre, Verizon uses a combination of aGPS and GPS. The aGPS is designed to pull a quick fix by triangulating on cell towers and the GPS chip then locks in to provide the more accurate reading you need for navigation. So, on Verizon's other phones, you can still use GPS in Airplane mode, but it may take a little longer to lock in your position. Obviously, to use a navigation program in Airplane mode, you will need an application that has the maps resident on the device. Programs like Google Maps pull map data as it needs it and must have an active WiFi or data connection in order to load map data. I am planning to drop by the Apple store today to look at the Verizon iPhone and will ask them the same question. If I get a different answer, I'll post the change.