I just got the iPhone 4 two days ago, and this is my first iPhone, so I'm not very familiar with the battery life or how to keep it running at it's best. I spoke with a representative at AT&T and she recommended that I shut it completely off and let it charge overnight so when I turn it on, it's received a full charge without anything interrupting it during the night. Also, she said that restarting the phone is how AT&T delivers over-the-air updates and how you "lock on" to the tower And keep the signal strong. I live in an area where there just so happens to be a broken tower, so I barely get reception at home. Coming from a Verizon blackberry (with full reception)I didn't know about their towers so I just assumed the reception was horrible and was going to bring it back to best buy & reactivate my blackberry while I still had time. But with that phone I never turned it off at night - just plugged it in. The one thing I liked about that phone was that even if the phone was COMPLETELY turned off, it would automatically turn itself back on if the alarm was set. Is there an app for the iPhone to make it do that? I still am using that phone as an alarm clock because I was unsure about leaving this one on all night so the alarm would go off. But I'm glad to see that so many of you don't turn it completely off. Well, thanks for letting a new user rant! 