XKCD Passwords
XKCD is an awesome webcomic of romance, sarcasm, math, and language. It often has UNIX shell jokes, and other sysadmin humour as well. One particularly funny comic strip focuses on how terrible passwords are for people to remember, but easy for computers to guess.
I’m glad to see various implementations on GitHub. The project named xkpa is my favourite. Easy to pass on to users (prevents additional back and forth due to insanely complex generated passwords), as well as indicating passwords entropy and average time to crack.