On the Wikipedia for Autodidacticism, there is a section labelled: Some notable autodidacts can be broadly grouped in the following interdisciplinary areas:
Artists & Authors
Actors, Musicians, and other artists
Architects
Engineers & Inventors
Scientists, Historians, & Educators
And, I have added (from my own research) Mathematicians, Philosophers, and anything having to do with Computers.
My friend has a website: http://www.autodidact.com/index/html and has written many books on the subject.
