cereal? out box. completed expense reports that need to be mailed? out box. mail that needs my wife's attention instead of mine? out box.
in the same way that a pad of paper lets me capture thoughts without acting on them immediately, the out box lets me stage items that need to be moved somewhere, without interrupting my flow of work. i can let go mentally of the thought that this item needs to be put away. when i do want to take a break and stretch, all these "somewhere else" items are in one place so it's easy to scoop them up and walk them to where they need to 