Did you know that light is a better transmitter of quantum computer information than any sort of cabling? Because it isn't altered by electric and magnetic fields, it would be perfect for carrying data if photons would stop being so snobby and interact with one another. Only highly-sensitive interferometers can overcome that problem, and they're so fussy that a mild sneeze near to one would wreck its calibration. Air Force
researcher Jonathan McDonald thinks he's got a solution: project holographic interferometers onto glass where it'll "freeze" and become much more stable. There are only two downsides: you can't edit the programming, nor would it scale very well, because you'd need physical space to set up the individual glass plates. On the other hand, the materials required to build one are all commercially available, and we're sure the Air Force has a hangar or two going spare, so perhaps we could see holographic quantum computers
in the near future -- or at least a very decent laser light-show.