The prototype comes in white as well as black. One of the big attractions of OLED technology is the brightness of the colors, along with the potential for energy savings and sleek, thin devices. (OLEDs don't require backlighting.) Some very small OLED screens--in the 2.5-inch range--are already in use in cameras and cell phones. Mass manufacturing could be a challenge, but Sony's not alone in trying out the technology; Matsushita (aka Panasonic in the U.S.), Samsung and .