I just finished RESTful Web Services, and I have to recommend it. It's a very clear explanation of what REST is, and how to think of your application in RESTful terms. Since REST was in my list of "gee, that might be important, but don't have time right now to track down all the implications from lots of different blogs with subtly different interpretations," I definitely appreciate the clarity of this book. It's given me ideas as well, always a good sign. One small problem was that there were a number of grammatical errors, the most distracting being the resolute avoidance of the subjunctive.