Ciao is also used widely in Germany, where it managed to confuse the hell out of me.

Me: Auf wiedersehen!
German Local: Ciao!
Me: Que?
GL: What?
Me: Ciao?
GL: Ciao!
Me: Why do you keep saying ciao?
GL: Because you're leaving, of course.
Me: Oh. Well, ciao!
GL: Auf weidersehen!