An awkward young man from rural Mississippi wins a scholarhip to Harvard University. On his first day at the campus, he approaches a couple of cocky New England socalites and asks, "Hey y'all, where's the library at?"
The socialites snigger, and one of them replies haughtily: "At Harvard, we prefer not to end a sentence with a preposition."
The young redneck thinks for a moment and says, "Okay. Where's the library at, asshole?"
(From Lost for Words: the Mangling and Manipulation of the English Language by John Humphrys)