Try asking a few of your friends or colleagues if they remember any rules of English grammar. Almost certainly at least one will say, "Never end a sentence with a preposition."
Bryan Garner wasn't the first to call it a "superstition":
The spurious rule about not ending sentences with prepositions is a remnant of Latin grammar, in which a preposition was the one word that a writer could not end a sentence with. But Latin grammar should never straightjacket English grammar. If the superstition is a "rule" at all, it is a rule of rhetoric and not of grammar, the idea being to end sentences with strong words that drive a point home. That principle is sound, of course, but not to the extent of meriting lockstep adherence or flouting established idiom.
(Garner's Modern American Usage, Oxford University Press, 2003)
For the complete article, go to Is It Wrong to End a Sentence With a Preposition?