If you haven’t already checked your iOS devices for a software update, it’s time to do so, if you wish to have a better battery life that is. Apple just released the iOS6.1.2 update for your iPhone and iPad that squashes one bug:
Fixes and Exchange calendar bug that could result in increased network activity and reduce battery life.
Unfortunately though, if you were hoping that Apple would fix the bug that allowed users to bypass the lock screen, then you’re in for a disappointment because the update does not address the issue so yes, you will still be able to gain access to the contacts and the phone function of a locked iPhone.
Nevertheless, do check for an update, at least your device might last a little longer after each charge. Update available via iTunes on your Mac or PC, or via OTA.