Lost your smartphone? Borrow a phone and send to your precious "lost" by SMS. Your phone will vibrate and make as much noise as possible to help you find it.
Not enough? It's way out of reach or stolen? Your smartphone will also send to the borrowed phone a SMS reply with its approximate location, precise location and remaining battery level.
Finally a notification will give at the person holding your phone a warning + ways to contact you to return the phone.