The Apress book, Pro PHP Programming, which I coauthored is available for eBook and print order now and will be in stores in a few days.
Apress
Amazon
Chapters/Indigo

I have written seven chapters:
3 - Mobile PHP
4 - Social Media
10 - Libraries
11 - Security
13 - Refactoring, Unit Testing and Continuous Integration
14 - XML
15 - JSON and Ajax

The Full Table of Chapters of the Book is:

1. Object Orientation
2. Exceptions and References
3. Mobile PHP
4. Social Media
5. Cutting Edge
6. Form Design and Management
7. Database Interaction I
8. Database Interaction II
9. Database Interaction III
10. Libraries
11. Security
12. Agile Development with Zend Studio for Eclipse, Bugzilla, Mylyn, and Subversion
13. Refactoring, Unit Testing, and Continuous Intergration
14. XML
15. JSON and AJAX
16. Conclusions

Appendix - Regular Expressions