While we’re still a long way off from the Star Wars telepresence holographic displays, this build over on the Projects site is the closest we’ve seen yet. Even better, it can be built in a garage for not much money.
Inside the Hoverlay are a few fans and a pair of ultrasonic atomizers that turn water into an extremely fine mist. The fans pull this vapor up through the base of the display and through simple drinking straws to create a laminar sheet of water vapor. Put a projector behind this thin sheet of vapor, and you have a display, seemingly floating in mid-air.
The base of the display can be scaled up, simply by putting several units together in a line. It’s still just a prototype – future versions will improve the stability and reduce the thickness of the fog layer – but it’s still a very cool build for a custom holographic display.