Install this free app on any other iPhone, iPad or iPod touch to get back your lost iPhone. Sign in with your member name and password to locate your missing device on a map. You can also wipe it to permanently delete all of your data or remotely lock the device to protect your privacy
It displays a message and optionally plays a sound for 2 minutes even if the device is set to silent. The app will automatically sign you out after 15 minutes and you must set up your MobileMe account and turn on Find My iPhone on each device you want to locate.