Draw on the wall [display technologies for untethered computing]

Today, the most exciting development in interactive technology is the untethering of users from their desktops. We can imagine scientific, engineering and business users surrounded by their data as they wander through their offices and hallways, talking to their applications, listening to the results and drawing on the walls. This represents a popular picture of smart environments and ubiquitous computing. In this article, I discuss the display technologies that will make this picture real. The component devices of these technologies have no magic; they obey the same laws of physics as the rest of the world. Of course, transforming these ideas into reality faces some unsolved problems. While the untethered computing world is inevitable, its details lack clarity, and the path to its realization looks rocky