The authors have a weblog at nudges.org that expands on the ideas in the book with plenty of examples.

Saying that Nudge is a "must read" for service designers is a big understatement. After having read this book while working in a customer experience team and having applied a lot of the ideas and concepts described by Thaler and Sunstein, I am convinced that you need to read this in order to have a complete understanding of the way people take decisions.

Although it is not the only book on the subject (Predictably Irrational by Dan Ariely and Irrationality bu Stuart Sutherland also come to my mind), Nudge goes one step further from only describing the ways in which people are "irrational" and actually provides a lot of concrete solutions for using this in the best interest of the users, clients, etc.