Ever heard about Heliodisplay?

Lets learn smthing abt
it-->

The Heliodisplay is a fog display developed by IO2 Technology. A projector is
... focused onto layers of air
and micro-spheres in mid-air,
resulting in a two-
dimensional display that
appears to float. This is similar in principle to the cinematic technique of rear projection and can appear three-dimensional when
using appropriate content.

Heliodisplay can work as a
free-space touchscreen when connected to a PC by a USB cable. A PC sees the
Heliodisplay as a pointing
device, like a mouse.