Geek has the story on this awesome 2-sided display out of Korea.
So you’ve got a touchscreen on your phone, but you can only touch one side of it. That’s pretty boring, right? A team of researchers from Korea Advanced Institute of Science and Technology (KAIST) have gone beyond a simple touchscreen and created a clear wall that can respond to touches on both sides simultaneously. Not only that, but the input from the two sides can interact in a variety of ways.
The so-called Transwall is currently mounted to a large T-shaped frame that houses a small square of the material. Of course, any real production version of this system would be an actual wall rather than a window like this prototype. The touch surfaces are standard sheets of plexiglass, but behind each one is an IR touch sensor that detects when someone is interacting with the plexiglass. Sandwiched in the middle is a holographic film that allows images to be projected on the wall.