I've long felt that the whole preposition-at-the-end-of-a-sentence thing was caused by the long time ignoring of the phrasal verb. The particle of a phrasal verb looks like a preposition and can come at the end of a sentence quite nicely. Then, when kids that had learned the phrasal verb naturally in the first few years of their lives were told by grammarians that prepositions should not end sentences and that the particles were really prepositions, rather than coming up with things like "up with which I shall not put," started putting real prepositions at the ends of sentences.