Ha, this looks awesome. This half dome projector screen is big enough for two people to sit in front of, and isn't just a damn prototype—the California company behind it actually has them for sale.
The dome screen measures 3 by 6 feet, and uses a special 18-inch mirror to reflect the image from your projector that's hidden away on the outside. In the pic above you can see the little hole that the projector beams through, but in the video below they've just clumped it on the desk.
The screen ain't super cheap at $1440 (including international delivery), but that's still about $3000 less than some similar products we've seen in the past. If you're a gaming junkie (particularly with racers or flight sims), have a projector lying around, and don't mind a little bit of skewed perspective around the edges, then this might be an alternative to a big screen HDTV. Maybe.