Since this thread was created, new buttons seem to have appeared, so for the sake of completeness here's a summary of all the ways you can now quote that
aren't physically editing text.
The Quote Button starts editing a new post containing a quote of the post in question.
The Multi-Quote Button - right next to it - is used to quote more than one post at a time. Select this for each post you want to quote except the final one, for which just press the usual Quote Button. This will create a single new post containing quotes of all the posts selected, including the last one.
Quick Reply To This Message - to the right of Multi-Quote - sends you to the Quick Reply editor at the bottom of the page, but only creates a quote if you then tick 'Quote message in reply?' in the Options underneath it.
↓ Over Here ↓