Find My iPhone app on the iTunes App Store -- a service previously limited to MobileMe's web interface. The App will find your iPhone or iPad or iPod touch should it be lost or stolen. So obviously, you don't install it on your lost/stolen device, you install it on a different iPhone, iPad, or iPod touch, yours or somebody else's (try a Starbucks). Panicked owners can then login with their MobileMe account to map their missing property and then remotely lock the device or wipe the data. The App can only be installed on iOS 3.1.3 or later devices and is available now for free.