Apple has an application Find My iPhone update. It is now possible to receive an email when an offline device comes back online and can determine its location. There is now an option for an offline device from the list here. Find My iPhone is a service that allows you a lost or stolen iPhone to find. You can see where the iPhone is located on the map, you can remotely erase everything on your device or play an alarm sound. The latter is useful if your iPhone somewhere between the cushions of the sofa or in bed are lost.
