Time Traveller was not holographic. It used a video screen reflected in a large concave mirror to make a pseudo-3D effect. There's a medical company called RealView Imaging claiming a "holographic" visualization system for surgeons that's pretty much the same thing.
couldn't resist though, it certainly made me "WOW!" when it appeared in the local arcade, might not have had R2D2 projecting it, but it looked like a hologram to me. Reading more, seems a better effect than the POV thing in the video