I'm not sure where you are at with this Jammerjay but I have found a few really cheap alternatives for using holograms. A local store here at the mall around a month ago had a simple hologram kit which requires a monitor. Basicly you lay the monitor flat and put this box over it which contains a mirror going diagonal across the box. When looked at head on it looks as if what the monitor is emitting is in 3d, pretty neat but yes your changes would have to be made for color, better render, and no interface but looks doable.
As far as following the user, you should be able to do this now until you can get the rest of the hologram portion worked out. This could be done with creative use of either a headtracker or modified use of a simple web can that is constantly checking the pixlecolor, and then scripting agent move tags to match. Hope this brings up some ideas.
-there would be no knowledge or wisdom.