As part of my research for my final project, I looked up some info on holographic projection, because I'm not crazy about head-mounted-displays (HMDs) or even stereo glasses--ultimately I'm thinking Holodeck! There are some promising developments in this area, that can be read about at the following links:
A Holographic Animation System
Holographic-like Sterogram Display
Summary of these papers: It is currently possible to project a 3D image into a 3D space, through the use of an LCD projector, a diffraction grating, a moveable mirror, and a holographic screen. The major limitation right now is how far in front of the screen the image can be projected--right now that distance is less than 10cm.