There have been a couple of uses that have been suggested by the patent, such as the use of the iPhone to unlock doors or to be used at a computerized cash register and could possibly even be used to pay for parking meters. The patent suggests how the iPhone and the secondary device such as a computerized cash register at a supermarket will set up a network with each other in order to communicate.
The user will approach the cash register and based on the signal strength of the Bluetooth connection from nearby cash registers, the iPhone will form a connection with the closest one thus opening up a variety of functions, such as the ability to make payments, check for product availability, etc. The same can be applied to parking meters, with the closest meter connecting with the iPhone from which the user can perform a variety of functions like topping up the meter, check time left or check the various rates.