Researchers at MIT have come up with a novel way to interact with wireless devices - a miniaturized trackpad so small that it can be stuck onto a user's thumbnail. NailO, as the device is called, is the brainchild of media arts and sciences grad student Cindy Hsin-Liu Kao, a native of Taiwan, who came up with the idea when she couldn't find the nail art stickers popular in that country in the U.S. She called the device "unobtrusive."