I decided this year since Lily is older that we would welcome the Elf on the Shelf. We didn't do the whole, read the book and no touching bit but I do tell her that he tells Santa when she's bad. We actually didn't even name him. I just say Mr. Elf.
He hasn't done anything too major yet but we're only on day 12 so perhaps he will before Christmas. I actually forgot to hide him 2 days in a row....oops!