When posting a reply, try scrolling down and pressing the "Insert Quote" next to the post you wish to quote. Similar effect.
Similar, but not very useful when you want to quote from multiple pages.
Think of it this way, there is thread which has 6 pages. You read it from the beginning and while you are reading through, there are a few comments that you would like to respond to but want to read the entire thread first. With the multi-quote feature you can just simply tick the posts as you go along and once you reach the end you just hit the reply button and it is all loaded in the text box.