Workday interruptions

Sometimes the workday winds to a close (or at 5:00 is just getting started) and I wonder what I've done all day. I figure I have an average of 5 minutes between interruptions, and during many parts of the day, I'm sure I go hours with no more than a minute between interruptions. I like to think that most of the interruptions are important, and require my contribution--this raises my perception of my worth: if things can't go on a minute without me, I must be very important!

The reality is that probably half of all the interruptions were 100% unnecessary, usually the result of people preferring to ask me questions rather than ask someone else more intimidating (or farther away), or surprisingly often, rather than actually think for themselves. So I was intrigued by LifeHackers recent post on avoiding workday interruptions. My favorite idea:

From Rustman

To really avoid interruptions, I would chiefly recommend never exhibiting any initiative or displaying any confidence in the work you do because otherwise you can end up being a touchstone for the rest of your workmates lack of skills.

More practically, I've adopted a variation on:

Logging interruptions or drop-bys and secretly keeping track of them, making a trend chart and plan around these high-traffic interruption times with some kind of blocking technique

I try keeping a log. When/Who/Why/Duration. I realize that many of the interruptions are important, so the only reason to "secretly" keep the log is so as not to make the legit interruptions feel like they're doing something wrong. So far, one of the byproducts is that I become more aware that each little thing is an interruption, and somehow it helps me get back on track when the interruption is over. It also has heightened my awareness to the fact that getting up and getting a cup of coffee is, in itself, an interruption, and by its visibility, begs more interruptions.

Any other great ideas?