Web Application Development with PHP 4.0 is a good book. It delves into concepts of web applications... something most books shy away from. The project that the book covers is phpIRC, definitely an advanced project. The book is written by the creators of phpMyAdmin, which we all know is a great PHP web application. When I first got the book I glanced through it and put it on my bookshelf for later. I couldn't even begin to understand it. But, after I became more familiar with PHP, the book has been very helpful. The CD comes with a few very helpful scripts - such as a function that will check if the text contains bad words. It's the practices they teach in this book that set it apart from others.
Anyway, I think you'll enjoy the book if your looking for something advanced.