Reports have released a patent filed by Apple for a configurable input system. The system can be made available for Mac or an iPod.

The technology goes like this: You take a ordinary iPod, attach a joystick to it and convert it to a gaming station, add a keypad and make it a phone and many of such stuff.
The base to the additions are the overlays that can be identified by the computer and make it respond accordingly. Similarly an iPod can be converted to a PDA, Cell Phone or a remote control.
You can also mess around with your MacBook in a similar manner. This would definitely boost the third-party designers to design something weird for the devices.
The entire concept is based around adding a physical control that can sense the additions and respond accordingly. Such a control will most probably be a Touch-sensitive pad or some other interface of similar type.
Via: macrumors