Sharp will start mass producing (read, it is not just a concept) a LCD monitor that can display two images at the same time and only the viewing angle determines which image the viewer is seeing. For instance you could see a PC desktop when looking at this Sharp LCD monitor from the left and a TV image from the right.

It works by directionally controlling the viewing angle of the LCD monitor. Using such tricks as putting a parallax barrier superimposed on an off the shelf TFT LCD, the monitor sends the backlight into right and left directions so the different information can be read from different angles on the very same screen at the very same time.
A shifting liquid crystal material makes this feature possible by preventing light from going to the left or right. When the user is done viewing sensitive information, they could switch back to a normal setting where all persons could view the images on the screen regardless of location.

However, the technology is not quite perfect: standing in front of the two-way LCD when it is in dual screen mode causes the images to overlap. Another problem is how users would deal with sound; Sharp recommends the use of headphones to combat the problem. Sharp thinks the dual view LCD monitor has uses in public information displays, as you walk by two different screens are exposed.