Just recently, a team of researchers at University of California Institute for Creative Technologies in Southern California, USA designed an array of small and inexpensive pico projectors to re-create images in a 3D holographic manner. The projector images send images slightly different from the previous one, which re-creates the illusion of volume.

This is one of the first models of its kind and it can be seen in this demonstration through this link: http://www.youtube.com/watch?feature=player_embedded&v=HwGiEUcHx9s#!