Ability to delete your own comments.

You should be able to delete your own comments. If we're worried about people destroying the continuity of a discussion, I'd be OK with limiting it to being able to delete it within X minutes or only if no one has responded after you.

I ran into this because I just barely posted a comment and then before the page had a chance to update, I hit "post" again and it posted my comment twice. That's probably a bug that should be fixed as well.