FogScreen: Another Lo-Tech Wonder

` A Finnish company called FogScreen has made a display screen out of... well... fog! With ceiling-mounted air jets, the FogScreen creates a vertical slice of air only a few centimeters thick, where turbulence-free layers flow side-by-side without mixing. Ultrasound vibrations are used to vaporize water into a very fine mist that is pumped into it, which catches the light of any old projector. If you want to use it as an infrared computer display, you can even use a laser-scanning system to detect where you click on it.
` Clicking would not distort it too much because the mist is constantly refreshing. At public shows, you could have a huge FogScreen which would restore itself in only seconds after people walked through it.

` After careful analysis, I have come to the conclusion that the FogScreen is neat, but not the most practical.

` Thank you for your time.