Can you use wi-fi to, say, use Google Maps, while on a voice call? I tried tonight while online in a drugstore. While on the call, I invoked the map application. I got an alert saying I couldn't use EDGE. Well, sure. There was an instore wi-fi network (password: linksys ) and the iPhone connected just fine, but I still couldn't connect to Google Maps. I thought that was supposed to work. Anyone tried this and got it to work?