Are you wondering what this is? FogScreen projects an image, using a standard projector onto a screen of fog created from tap water and ultra sonic rays. Lasers attached above the screen allows a touchscreen functionality as well. Although the resolution and quality may be diminished by the nature of the fog, the FogScreen looks like it may be the advertising billboard of the future.
For more and detailed info Transliteracies has more info. But first you should check out this coverage of the FogScreen on YouTube:
(Via TechEBlog)