The full face-side of this device will be nothing more than a display, much like the iPhone is today, while the back-side will be primarily dominated by a force-sensitive touch based surface. Your fingers, which act as a cursor, control the face-side UI by the back-side etched controls.
The dramatic design will offer users a variety of interfaces or modes to work with including one for a phone, text messaging, a traditional iPod, a camera mode and more. The design may also, according to Apple, simply offer consumers with a dual-sided display option in lieu of a force sensitive controller surface.
According to the report, it is unclear how the etched controller idea would work. Would they be interchangeable or preset or could the back surface change itself.
Apple credits John G. Elias part owner of the former FingerWorks as the sole inventor of this patent application. Elias is now working at Apple on other touch related patents.