Has anybody done anything with fiber optic type stuff?
Sure! Back before the small SMD LEDs were available I used plastic fiber optics (they look like mono-filament fishing line) to illuminate head and tail lights on N scale cars. The fiber optics would be bundled to exit under the car and be illuminated by a single bulb under the layout.
I also used fiber optics to simulate lights on an N scale Christmas treel Again, they were bundled under the layout and illuminated by a single bulb. On those I painted the ends with different color Sharpie markers to make them look lime multi-colored lights.
In another project I used fiber optics to illuminate walkways inside a N scale power plant building. Those were bundled together and illuminated by a white LED. This was a more recent project.
Another application was to illuminate lights over a doorway on the outside of a N scale building.
Fiber optics have a very directional output. You can employ some tricks to widen the view angle, but that also results in reduced brightness. Now that very small SMD LEDs are readily available, those in many instances can replace fiber optics. But they still are usable in certain applications.
