We always thought the window was pretty mature technology, but Samsung's here at CES to prove us wrong. The Smart Window, currently in prototype phase, casts a touch-controlled interface onto transparent glass with ambient light. Samsung was demonstrating a whole range of applications, from Twitter to Microsoft Office, all touch-controlled and viewable directly on the glass. Images are viewable in daylight, and there's a nighttime mode that uses side-lighting and flipped colors. You can even draw some virtual blinds to control the flow of light. It's difficult to see how Samsung might turn this into a commercial product, but it definitely looks more useful than a transparent TV.