The LG DoublePlay is a T-Mobile device that has dual-screens - a primary 3.5 inch display and a smaller one sitting beneath that. The display is revealed by sliding the top portion of the device up. On each side of the secondary display are keys to make up a split hardware QWERTY keyboard. The device also has a 5 megapixel 720p HD camera with flash. Unfortunately for software, we're only getting Android 2.2 with LG's UI.
Early press shots suggested the display would be used for launching apps when inside another but T-Mobile has described it as having more functionality than that, saying you'd be able to keep up with your social life without having to leave a game, a website or any other application.