On allot of forums there is a quick response to topic box that displays after the end of the thread page currently being viewed. It doesn't have all the options of the full edit window (like direct quoting)and is a trade off in bandwidth usage.
But it would also make it so that the Post a new _ window doesn't have to be opened for every response. I could see it helping with discussion threads if they start going quickly or making it possible for Spamville to go even quicker than before. Then again that also is a double edged sword. There are times already when Spamville goes too fast for some people.
So I leave this suggestion open and wonder what other people think of the idea.