If I said to you, "You're not in Kansas anymore," would you know what I was talking about? Where do you live? And how old are you?
Is there a non-American equivalent?
All I came up with on my searches were movie and pop culture references. :)
EDIT: WOW, thanks, everybody! I definitely got the information I needed.
I didn't put what it was from in my post, of course, but most of you know it's a deriviation of what Dorothy says in The Wizard of Oz when she walks out of her house after it landed in Munchkinland.