Back in my Pre-GUI days, I used ALT codes quite extensively. 99% of people had no idea how to access a folder called "Æl*" (ALT+146, ALT+255) for love nor money...
It's fairly popular on a board I am morbidly fascinated by, sort of interesting seeing kids "discover" this all over again.
EDIT:-
wow.. this board takes objection to ALT+255... it should be whitespace, not an asterix... when typing it, it was, but after posting, "hey, I'm an asterix now"