I used to have a friend who you would call a flibbertigibbet.
Plus the word flibbertigibbet keeps popping into my head from time to time. It guess it must be a favourite word or something.
EDIT: Definition of Flibbertigibbet from Wikipedia
Flibbertigibbet is a Middle English word referring to a flighty or whimsical person, usually a young woman. In modern use, it is used as a slang term, especially in Yorkshire, for a gossipy or overly talkative person. Its origin is in a meaningless representation of chattering.  It does not always apply to females, however; it has also been used to describe Jiminy Cricket due to his whimsical, chatty nature.