Initially, I learned it for fun and ham radio emitting. But I find it fascinating that you can use it with anything that can be turned on and off with a rythm.

I used a flashlight to say "hello" while waiting for a fireworks event, but the other person far away just blinked their flashlight randomly in response.

I guess it could be used for worst scenario speech, like blinking eyes for examples if I ever have a terrible accident somehow (has been used by tortured persons, see https://www.youtube.com/watch?v=WZ256UU8xJ0). When I saw Tuco’s grandpa in Breaking Bad taking so much time to write words with his bell, I just tought about using morse (but with something more elaborate than a bell, because you want to use long and short tones; same problem applies if you want to knock on walls or doors).