Fujitsu has an extensive range of Tablet Lifebook laptops, and the U939X is a 13.3-inch 360-degree convertible model. It's small and light, but packs in a lot of high-end features, including a stylus that sits in a housing on the base and Fujitsu's PalmSecure biometric authentication. Indeed, according to Fujitsu the U939X is "the world's lightest business convertible in its class".
Fujitsu Tablet Lifebook U939X review at ZDNet