Sean O'Reilly is the author of How to Manage Your DICK, the book that introduced the world to the concept of Dick Management. The write-up from the back of the book describes him as "an emerging leader in the rapidly evolving field of personal development, life improvement, spirituality and travel."
He has also edited the following books:
In addition, Sean O'Reilly happens to be the brother of Tim O'Reilly founder of the O'Reilly and Associates publishing company, known for excellent niche computer books. (I'll bet that's an interesting family.)