I was in Toronto today, using 3G and GPS to navigate myself there. I wasn't using it as a GPS, with the screen on constantly. The phone lasted about 3 hours before I got the 20% warning. I have calibrated the battery. I had WiFi off, 3G on, location services on, and bluetooth off. I used the phone for a not-even-5 minute call. I was also listening to reasonably-encoded mp3s on the way. When I turned 3G off, I found it to last a little longer. Now I'm going to be in Korea in a about a week. If Korea only supports 3G, I'm going to have to leave 3G on all the time. Has this been other people's experience?