When I travelled to Boston, I took my recently received copy of "Advanced PHP Programming" by George Schlossnagle.
I have still to finish the book but I can already recommend it to anyone curious about PHP.
I warmed to the book immediately. The succinct, introductory chapter on coding styles covers what it needs to, and no more. It shares the ethos on logical structure and clarity behind George's work and doesn't preach. As a development manager and architect, I've done a lot of code reviews. I've split blood and tears (mostly mine) to train developers and bring code up to scratch. Chapters like this remind me there are other people who understand that code is literature.
The book is a deep resource on development in PHP. There is a lot on tuning, and it covers techniques, algorithms, operating systems, testing, OO, and PHP internals. Even if you are not building a system that needs to scale, read this book.
The book was published a year before fluent interfaces and test driven development caused a buzz in the PHP community. George covers both. It is obvious that leadership and knowledge is being shared and I am glad to own a copy.
PS. I've met George a couple of times at conferences. This photo is from OSCON last year.
From the left: George, Wez Furlong, me, Andi Gutmans, Richard Rendell.