This is a great read. I am a strong introvert, and alot of this article rings true for and how i need to work. I need time space to do my thinking and work. Which been an enterprise architect alot of the time is just noodling and mind exercise on how things will fit together, and interruption can break a train of thought.
Go read these articles and get some insight to the world of the introvert.
My preferred method of saying I'm busy is the use of music, or more to the point headphones. When I have those on people at work know that I would prefer not to be disturbed. On days when the office is very disruptive I use my Shure noise canceling headphones.