Wondering how the iPhone geotags the photos? I really like it when it does that and I suspect that it uses a combination of GPS (satellite) and cellular towers when it does that. Since my carrier charges me for receiving text messages when I am abroad, I was wondering if there was a way to put my iphone on airplane mode, so i would not be able to receive any messages or calls, but still be able to have the photos geotagged? This will prove most useful for vacations abroad. Thanks.