I recently came across a great Slideshow from Michelle Villalobos' workshop "You're Not Crazy… It's
Just Your Personality Type." This is a wonderful overview of personality type theory, MBTI,
and how it applies in business.  This is a rather thorough review if you are willing to take the time.

My good friend and colleague, Mary Jo Asmus has just posted the second in her own series on leadership and the introversion / extroversion conundrum. You can read both here:

Introverted Leaders: Gifts and Cautions

Extraverted Leaders: Gifts and Cautions