Quick search, first hit:

"Usage experts acknowledge that none is sometimes singular and sometimes plural. They mostly recommend that you treat it as singular when it means not one, or no amount, and plural when it means not any. None of that will get you doughnuts, or coffee. But it's sound advice, nonetheless."

Edit: should have mentioned that I agree that "none" is usually plural. Or, at least, singular "none" sounds vaguely prissy to me, in the same way as contorting sentences needlessly to avoid splitting an infinitive. To needlessly avoid splitting an infinitive, I mean.

James Thurber wrote some great essays on this general topic, citing, among other examples, an argument he had with one of his grade school teachers, who, having explained the proper use of some obscure part of speech that she rendered as "the container for the thing contained," objected to young James's suggestion that there should be another version that referred to "the thinger for the thing contained."

She challenged him to provide an example. He, of course, already had one in mind, from a vaudeville turn he'd recently seen:

Second banana: "What happened to you? You look terrible!"

Comic (disheveled, big lump showing through his fright wig): "Some guy threw tomatoes at me!"

Second banana: "Tomatoes? How could tomatoes do that to you?"

Comic: "They were still in the can!"