While not quite as good as its predecessor (PHP and MySQL for Dynamic Websites 2nd edition) in terms of readability and ease of understanding, Larry Ullman is still, with this book, miles in front of pretty much any other technical author I have read. The chapters on object oriented programming are certainly the best I have come across on the subject.
There is also a quick but useful demo of how to put a bit of AJAX in to a PHP site to increase usability.
The one thing missing from this book that I personally would like to have seen, would be an introduction to frameworks.
But let me stress this point: Larry Ullman is the best technical author, by a long, long way, on any subject I have ever read about in my life. I just wish he was an expert and wrote books on all the other things I want to learn about - that's how good his teaching ability is.