I wonder how big systems like Oculus Rift will become. OR (I'll call it for short) is a virtual reality system that fits like a mask over the face. And as Donald Clark says, "Once you flood their field of view with a screen that has a high refresh rate with rock solid tracking so that your head movements mimic what would happen in that world, along with great audio – you’re there. That new world is your reality." I really should get me one of those. This article classifies OR reactions and provides a video of one person "freaking out" in the environment.