Find My iPhone is free for anyone with an iPhone 4, iPad, or 4th generation iPod touch (iOS 4.2 or later required).* Just sign in with your Apple ID on your qualifying device and turn on Find My iPhone to allow you to locate it. Then use the same Apple ID to turn on Find My iPhone on your other iOS 4.2 (or later) devices including iPhone 3G, 3GS, or iPod