On PHPMaster.com there's a continuance of a previous article about security in PHP applications talking about a few more considerations when trying to make things secure.

In a previous article, I talked about some common security vulnerabilities that can affect your PHP web application. But there are other things besides those ten (okay, seven) attacks to think about when you’re developing. And so, this article offers a compendium of miscellaneous things that are security related; things you should do, things you shouldn’t do, things that other people might try to do, whatever it takes to make an article long enough for my editor to be satisfied with it.

He talks some about the settings that you might need to tweak in your "php.ini" server-side configuration file, some hints on filtering data (like using filter_input) and what to watch out for with error reporting. He also mentions session fixation and the protection of user data and passwords to keep them out of the hands of would-be attackers.