During the Fallout 4 presentation, Bethesda's Todd Howard revealed a special edition of the game will be released with a full-sized Pip-Boy that you'll be able to wear on your wrist.
More than a cool little bonus, you'll be able to put your mobile into the device, and through the download of an App, use it as second screen to operate your in-game Pip-Boy with.
No price was given for the Pip-Boy edition, but the App will work even without the device, and will be available on iOS and Android come the game's launch.