Very nice one,
This review is from: Professional PHP Web Services (Paperback)
I think it's a nice book, good job! It introduces wide range about the relationship between PHP and the web services, it's a good base to start. However I have to tell, that there are some bugs (or the descriptions are not clear, don't know) in the example sources, for example I've found one in the chapter about security (Chapter 6).
This is a problem, but with it, I still could recommend this book for everybody not familiar with Web Services, and would like to learn all the related technologies. As it is true at other books, too: you can learn all these things from the web, but you can just find these together in this (or other) book, and you can read it conveniently at your bed with your girlfriend. :)