The world's first truly dual-screen laptop, which will allow computer users to multi-task while on the move, is due to go on sale by the end of the year. One of the first photos of the gScreen Spacebook Photo: GIZMODO The pioneering PC, known as the Spacebook, is the brainchild of Alaska-based technology firm gScreen. The gScreen Spacebook will boast two 15.4 in screens which can slide away to fill the space of a single screen when the laptop is being stored or transported. Gordon Stewart, the founder of gScreen, told the website that the first Spacebooks should be available...