Thread: Tell me about quotation marks

The question I'd like settled once and for all is how to place periods and commas in relation to quotation marks. Example:

He said it was an "accident," but we all know the truth.

as opposed to

He said it was an "accident", but we all know the truth.

I have the impression that putting the comma within quotation marks is something my teachers have been teaching me since I first started school, but in more distinguished writings it seems that having the comma outside of the marks is perfectly acceptable.

The only universally accepted rule I'm aware of is that the comma is put within the quotes for story dialogue:

"This whole comma thing is ridiculous," said Lëzen.

Anyone know WTH's up with all this?