Pretentious Parlance on Preposition Placement

Like most people, my parents raised me on the notion that a preposition is one of the figures of speech you should never, ever end a sentence on.  However, as you can see, doing so has not caused me to spontaneously combust - while like any good grammar-cop I am, of course, impervious to flames, my keyboard isn't and typing with melted keys poses a huge pain in the butt.  Truth be told, this supposed tenet of English grammar is an antiquated myth, tracing back to an 18th-century Anglican priest named Robert Lowth.

Given the richness of English-language literature written previous to the 1700's, the marvel here is that it stuck. Much of the Western world at the time had been in love with the Roman Empire since the sixteenth century; perhaps Lowth's seemingly arbitrary rule resonated with them due to its closer kinship with Latin grammar, or maybe it simply clicked because "preposition" means, literally, position before and I guess punctuation isn't a good thing to be immediately before.  Poor punctuation.  Nobody loves you.

Over the course of three hundred years, even the most out-of-left-field rule, let alone one with that odd sort of irrational but present resonance, has plenty of time to become ingrained.  This one has done so.  What this means in application is that whether or not to end a sentence in a preposition poses a choice, not of grammar, but of style.  Are you writing in a conversational tone?  Or is your current project of a more formal nature?

If the former, please feel free to plunk that preposition down right at the end of the sentence, if that's what reads most naturally.  For example, I want you to picture someone who actually, in day-to-day conversation, would say "On what did you put my glasses?".  They're wearing a monocle, aren't they? And possibly a top hat, and maybe they're smoking a pipe.  If not, please amend your imagination, because the convolutions sentences undergo, when their most natural ending is a preposition but their writer adheres fervently to Lowth's rule, ought to be classified as some kind of stylistic contortionism.  That sort of thing just doesn't fit a comfortable, conversational tone at all, and that's a pretty mild example.  "Looked for the cat had not even been" doesn't just sound stuffy.  It sounds like fricken' Yoda.

On the other hand, in formal writing - or in writing dialogue for a very formal, proper character - knock yourself out with the contortionism.  This holds especially true for projects like cover letters and thesis papers, in which the reader's opinion of your grammar might hold direct influence over your future.  Which is more important, in the long run: writing a natural-sounding sentence, or joining the ranks of the employed?

...I thought so.

One condition, however, most definitely applies, both to prepositions at the ends of sentences and prepositions anywhere else.  It's also a good stylistic rule in general.  Don't use extraneous words.  "Where are you?" is an entirely reasonable question.  So is "She fell off the desk," assuming she had a valid reason to be up there.  Even if she didn't, she's the one in error, not the sentence.  Make those "Where are you at?" or "She fell off of the desk," though, and...well, if that sentence became a human being, it would be a lanky buck-toothed chinless chicken-necked zitty teenager at the wrong school's prom in a tux four inches too short.   Don't inflict that on it.  Nobody, not even a sentence, deserves that sort of embarrassment.