A group of Japanese scientists have created a touchable 3-D image using a combination of holograms and ultrasound technologies.
"Using ultrasonic waves to provide the resistance and tactile presence, the hologram simulates the sensation of rain drops or a small ball, all without interfering with the projected 3-D image. A couple of Wiimotes provide the tracking, and the programing provides the fun."
This would be a great application to apply to Video Games. Of course the Porn industry will most likely get there hands on this first...!
Check out the video demo on this link: