I spent the holidays touring Spain (my son was finishing a semester of study there). I turned on flight mode as we left the US and let the phone work as it should.

I have the 2400 mA battery, and through a week in Spain and 100-plus photos with the camera, the battery lasted until we got home, made a few phone calls and slipped it back into its cradle.

While I did have a spare battery and charger with me, that was pretty impressive service compared to previous cell phones.