Engineers at Apple have applied for a patent concerning incorporating solar power into mobile devices. While using solar cells to charge portable devices is not new, the approach covered by the patent application involve placing them underneath a touch sensitive display such as those used in Apples iPhone and iPod Touch. Most of the real estate on portable devices is already devoted to user interface controls, displays and the like, leaving little to no room for solar cells. Size matters when it comes to powering the units and the larger the solar cells, the better. Apple's approach would be to utilize the area already used by the screen to by stacking the cells behind the touch sensitive layer and screen.