If you haven't seen 3D on a video screen and are Las Vegas, you can see a large Sony demo room at MGM Grand. It's back near the entrance to the Monorail on the casino level.

There are no demos that aren't computer animations, so you are probably looking at games for the Sony game console. They use viewing glasses tethered to the screen and probably use the switchable glass that can be electronically made transparent or opaque very rapidly. The effect is quite good with the animations I saw.