WWDC 2009, Apple has built a service that works with the new iPhone 3.0 software launching on June 17 that helps absent-minded people locate and retrieve their lost iPhones in a variety of situations. If you absolutely cannot find your iPhone, perhaps the battery had died. You can send a "remote wipe" command to the phone to more-or-less self-destruct the next time its activated. A new section called "Find my iPhone" on your Mobile Me account will allow you to send a remote command to your iPhone, which will report back a GPS reading and pinpoint its location on a Google Maps anywhere in the world. You can even dispatch a message to your phone that will be displayed on the phone's home screen, like the picture. Think something like "This phone has been lost". For those instances where the iPhone is lost somewhere in your own home, you can instruct the phone to emit a series of loud pinging noises so you can track it down. All of this works in the exact same way, regardless of whether or not you've left the phone in silent mode.

You can wipe all personal data from your iPhone if you cannot locate it