American standard usage is to put the final period inside quotation marks, but (I believe) British standard usage is to close the quotation mark then have a period. (But what of Canadians?) I often find myself doing it the British way. It just seems more natural to me, as a matter of grammar, although typographically it's prettier to have the period inside the quotation marks.

Okay Bitt, double or nothing: You want to end a sentence with a quotation of a sentence (e.g., Bob said, "you must be crazy."). In standard American usage, you'd have one period, inside the quotation mark. In British usage, what, two periods? And furthermore, if you want to have a footnote at the end of the sentence to say where you got the quote, where does that go?