If want to buy an unlocked iPhone and use it more like an iPad--for PDA, WiFi and also for its GPS capability--what can/cannot I do without a SIM/G3 carrier contract (besides the obvious inability to make calls on the network, etc)? I am considering getting a MiFi device and use the iPhone as a WiFi device only. I assume I can use its WiFi capacity to use Skype for calls/txts, right? What about accessing Google Maps and using the iPhone as a SATNav--is that possible without the G3? Thanks in advance for your advice!