What if instead of a home button, your iPhone had a button that could also serve as a joystick? It seems like a pretty wacky idea, but the engineers at Apple have already thought of how such a mechanism might work. A patent application from Apple describes a “multi-function input device” that could one day change the way we interact with our Apple gadgets.

The idea, at least on the surface, is relatively simple. The home button on a gadget such as the iPhone or iPad could pop up, providing the end user with a joystick for navigation. Here’s how Apple specifically describes it: “In the first mode, an input portion of the multi-function input device is flush with the surface or recessed in the surface and is operable to receive z axis press input data. In the second mode, the input portion is positioned proud of the surface (i.e., project from the surface) and is operable to receive x axis input data and/or y axis input data.”

Apple suggests there are some use cases for a joystick, particularly obvious ones like gaming, but it also admits that additional input options might expose internal hardware and may even ultimately frustrate the end user. Those sorts of limitations may prevent something like this from ever coming to fruition, but wouldn’t it be cool if Apple was able to work this out?