MojoKid writes "Engineers from Apple have applied for a patent on an 'emergency' mode for cell phones that would squeeze every last drop of energy out of the batteries. The phone would recognize emergency calls when the user dialed an emergency number, such as 911 in the United States. But another number could also be stored as an 'emergency number' on the phone (a spouse, child, or parent, for example) or the user could manually put the phone in emergency mode. The process would do a variety of things. It would disable 'non-essential hardware components' and applications on the phone, reduce power to the screen and potentially reduce the phone's processor speed. It also would make it harder to disconnect the call and enable 'emergency phrase buttons' on the phone."