this one) that outlines virtually every conceivable way in which an iProduct equipped with NFC (Near Field Communication) could wirelessly interface and control a similarly NFC-equipped gadget, doodad or whatsit.
Many examples are given in the documentation -- everything from using your iPhone to control your house's thermostat to its automated sprinkler system -- but we're mostly interested in its applications as a gaming interface, of which two main methods are shown.
First, figure 44 shows how an iPhone can be linked with a familiar looking NFC-equipped controller by tapping the two devices together. Once paired, the iPhone can then be used to play the game rather than the controller itself, via on-screen controls. The phone recognizes the game being played (in this case, Prince of Persia) and displays three controller layout options: Classic, Custom or Game Developer Recommended. Selecting one of the three options causes a button layout to appear on the screen.
In the other gaming-centric example given, the iPhone is shown skipping the controller and interfacing directly with a gaming console via infrared, wireless internet or NFC. If NFC is present, tapping the iDevice to the console initiates the link; alternatively an RFID tag or QR code may be substituted to establish the connection.
For the system to be functional, everyone involved in every step of each device and piece of software will need to be on board. Console manufacturers will have to put NFC chips in their wares, game developers will have to code iOS device support into their products, and Apple themselves will have to release a version of iOS that actually does all this stuff.