We've had the ability to locate, lock, and send messages on lost Apple devices for some time now. But with iOS 6 and iCloud, there's a new feature called Lost Mode, which'll let whoever is keeping your precious iPhone make a call to a specified number. You can also use this to remotely track an iOS 6 device—you'll be able to see its point-to-point movements across a map instead of just finding its current location. Neat! Terrifying in an Orwellian sort of way, but neat!
Obviously, you'll want to enable this before the sucker gets stolen, or else you're out of luck. To do this, go to Settings > iCloud, and toggle the Find My iPhone option on.
And now's a good time to note that the instructions and screen shots in this tip were made with an iPhone in mind, so if you're using Lost Mode with an iPad, for example, things'll be different.
So then the phone is taken or lost. What now? Well, after your murderous, vengeful rampage, what you'll do is log in to iCloud.com and click on the giant Find My iPhone icon.
Then click on the Devices button, choose the one you've lost, and check out its info window that pops up.
Not only does it now show you the phone's remaining battery life (great, I can panic as I watch it slowly die), you'll see the new Lost Mode choice there. If you select that, iCloud.com will walk you through some steps. First, if you don't have a passcode set on the device, iCloud will make you pick one.
(If you already have a passcode set, iCloud will use that existing one to lock it down.)
Then you'll be given the option of adding a phone number where you can be called.
Finally, you'll get to type a message to display.
After that, the person who "found" your iPhone can actually call you from it instead of being locked out completely.
Also—and the paranoid should probably skip to the next paragraph—after Lost Mode is turned on, you can use iCloud.com to watch the progress of your phone as it travels from place to place.
Once you've found your device, either enter the passcode you set before to disable Lost Mode, or turn it off on iCloud.com by clicking the Lost Mode button again and choosing Stop Lost Mode.
Finally, know that you can also start Lost Mode from Apple's Find My iPhone app using very similar steps. The device that configures Lost Mode doesn't have to be running iOS 6, but you can't actually invoke it on one that's not. Make sense? Or are you both paranoid and confused now?
Sorry about that.