According to Apple Insider, Apple Inc. is looking to patent a design for a handheld device - or iPod - with a two sided display system. The back side would receive user input via a large touch- and force-sensitive screen interface while the front side would display the output on a smaller screen.

"Although a touch-screen interface could be embedded in or overlaid on the display, the use of even a single finger for input may occlude a significant portion of the display or cover more than a single operational control element," Apple wrote in the filing. "While this problem could be mitigated by limiting the touch area to a portion of the display screen (e.g., the display edges where horizontal or vertical motion could emulate slider controls), a single finger could still cover a substantial amount of the useful display area."
While this patent, filed in January 5th 2007 at the United States Patent and Trademark Office, might not become a real product anytime soon, it shows Apple's interest on taking advantage of the iPod's huge success to bring other uses to the portable player - the iPhone for example . According to the filing, this technique could also be applied to other devices such as palm or hand-held personal computers, tablet computer systems, mobile telephones, personal digital assistants, portable video players and portable audio players.