A TV with no screen? Sounds crazy, but Chad Dyner at MIT's MediaLab thought of it and created the Heliodisplay a couple of years back. Made by IO2 Technology, the Heliodisplay actually forms floating 2D images in midair from regular video inputs — essentially a virtual 30-inch video screen. It's not holography; it works by affecting the properties of the ambient air above the "projector" (about the size of a desktop PC turned on its side). While the images can't actually be touched, the display can respond to the movement of your hand, making it a virtual touchscreen.
Now the technology's getting an upgrade. The new version, called the Heliodisplay H3, can display video with 1,024 x 768 "pixels" (good enough for your basic HD signals) and uses an improved system to make the image more stable, uniform, and bright. The tech has a long way to go before it can really compete with the flat panel in your living room, but progress is progress. And, yeah, the $18,400 starting price is mighty steep, though it wasn't too long ago that plasma sets cost about the same.
Check out some video and a couple more pics of the new Heliodisplay H3 in action after the jump. If, in fact, you have a Heliodisplay, let us know how watching a video of a virtual TV on a virtual TV looks.