Drive: The Surprising Truth About What Motivates Us -- Dan Pink (http://www.amazon.com/Drive-Surprising-Truth-About-Motivates...)
Linchpin: Are You Indispensable? -- Seth Godin (http://www.amazon.com/Linchpin-Are-Indispensable-Seth-Godin/...)
The Laws of Simplicity -- John Maeda (http://www.amazon.com/Laws-Simplicity-Design-Technology-Busi...)
Zen and the Art of Motorcycle Maintenance -- Robert M. Persig (http://www.amazon.com/Zen-Art-Motorcycle-Maintenance-Inquiry...)
Invisible Man -- Ralph Ellison (http://www.amazon.com/Invisible-Man-Ralph-Ellison/dp/0679732...)
How to Win Friends and Influence People -- Dale Carnegie (http://www.amazon.com/How-Win-Friends-Influence-People/dp/06...)
The Kindle app has really got me buying a lot of books that I now need to finish...
The reward scheme is dubious though: I love working on open source because it's intrinsically rewarding. But if you try to pay me a few bucks, chances are I'll lose interest because my day job pays better.
Extrinsic motivation killing intrinsic motivation is a known phenomenon in psychology: http://en.wikipedia.org/wiki/Motivation_crowding_theory It means that splashing money around to get people to do stuff can have the opposite effect. Also see the book Drive by Daniel Pink: http://www.amazon.com/Drive-Surprising-Truth-About-Motivates...