ADD is not particularly rare in my experience--certainly among hackers and entrepreneurs--and people that feel that they are special need to get out more. It's not a personality type as much as a processing mode(s). There are a number of good books full of practical advice on how to manage ADD. Three I have found particularly useful are

ADD Friendly Ways to Organize Your Life by Judith Kohlberg http://www.amazon.com/ADD-Friendly-Ways-Organize-Your-Life/d...

Driven To Distraction by Edward M. Hallowell http://www.amazon.com/Driven-Distraction-Recognizing-Attenti...

Healing ADD by Dr. Daniel Amen http://www.amazon.com/Healing-ADD-Breakthrough-Program-Allow...