I know this really isn't a major consideration when choosing a knife, but the other day I was sitting on my computer opening and closing my Hissatsu 2, when my roommate knocks on my door and asks what I was doing because he could hear the snapping sound of my knife in the other room, and it just got me thinking. All I have are liner-locks, and naturally they all make a rather noticeable clicking sound when they open. Was just curious if anybody knew of any really silent liner-lock or lock-back folders that don't click or make any sort of noise when you open or close them.