Reducing distractions
I've found that the number of visible open loops near my work space was hugely distracting. I moved my in box to a shelf near the door to my office - easy for others, but doesn't "bug me" on the corner of the desk.
I also added an "out box" - a magnetic file holder to the outside (vertical end panel) of my desk. It's out of sight while I'm working, but allows me to drop in anything that needs to be done away from my desk - something for the shredder, another person's mailbox, files that need to be filed out of my office, outgoing mail, etc. Then, it's "safe", but not distracting me... and reduces the number of times I interrupt myself by getting up from what I'm working on unnecessarily. When I do get up, I usually have 5-10 items in it and feel good about taking caring of them and getting a little break at the same time.
It may sound silly, but it works for me.
So, if I had something for someone else (internal/external mail), it would sit temporarily in my outbox, but then I would get it on its way. If it was something that they actually did have to pick up from me and they weren't coming today, I would file it in my tickler file.