Ok, 3D cave pictures aren't new and they're cool if done well enough. I know of a couple of amateur cave photographers who have shot in 3D and occasionally they put on a very neat slide show.
Well now the next step is with digital photography and printing the pictures in 3D as well.
Check this out.
http://www.photo3-d.com/
This would mean your caving models would have to stand still long enough for the flashes to re-charge and go off again with them in the exact same position. Worth a try I think.