wait, what?

I'm working up a grammar rant for the near future, and I ran across that Inhabitatio Dei has one of those Hauerwas apocryphal stories:

So this one time, Stanley Hauerwas was at Harvard to deliver a lecture and, being there early and still need to do some preparations, set out to find the library. Not finding it he stopped a student and proceeded to ask him, “Excuse me, where’s the library at?”

The student, looking incredulously at him responded, “Sir, at Harvard we don’t end our sentences with a preposition.”

Stanley paused for a moment and then rephrased his question in a more grammatically appropriate manner: “Where’s the library at, asshole?”