[jackhack]

Am I the only one to recoil at the thought of someone chewing transparent aluminum foil?

The potential is tremendous in aviation. Imagine transparent aircraft skins -- the superstructure and internals (fuel tanks, hydraulics, etc.) could be inspected without disassembly (which itself adds stress to the structure). Though I'm not sure passengers would take kindly to aircraft with transparent skins. Sometimes it's best that things are hidden under a bonnet.

[lainga]

You could wrap the cabin interior with OLED panels that are normally active and opaque during flight.

Then, when you're on a longhaul and it's time to wake the passengers up - turn them off in midair. Good morning!

[jackhack]

Brilliant. If the sudden increase in luminosity didn't wake you, the screams of fellow passengers looking through the invisible floor at the ground/Ocean 30,000 feet below would surely do the trick!