This was an interesting, last minute addition to a kitchen Leon and I recently finished.
Client insisted upon a back-lit shelf to show off some art glass pieces. Your wish is my command:
Solid hard maple shelving; 1/4" Lexan polycarbonate sheeting for light diffusion; with lighting built-in to wall behind; magically hanging on non-square, non-plumb, curved wall, with NO visible hardware/means of support insisted upon; ... and oh yes, the piece has to come off the wall easily, and the Lexan must be able to be changed if accidentally scratched in the future (if I told you how I did it, I'd have to kill you) :)