For those that were made miserable by the Passcode lock bug on iPhone 4.0, I am pleased to report that 4.1 fixes this. Traditionally if you set a passcode lock, you also pick a time amount before you have to enter the code. Thus if you pick 5 mins, you can turn the screen off, and if you turn it on again anytime before 5 minutes, you don't have to type in the code. The bug was that this time-out was deactivated. So in 4.0, with passcode lock on, even if you try and turn the screen back on in 2 seconds of turning it off, you have to enter the unlock code. 4.1 is BACK TO NORMAL!!!!!