Find My iPhone
If you’ve lost an iPhone and you haven’t signed up for MobileMe, you know the pain and misery of trying to track it down without Find My iPhone. with iOS 4.2 you get free, that’s right free, Find My iPhone. There is a catch, you need to set it up with an iPhone 4, iPad, or 4th generation iPod touch. Once that’s done, you can find all your iOS devices.