With yet another quality resource for the community, PHP Magazine has linked a site called Aesthetic Theory with tons of PHP tutorials on a load of topics.

Some of the tutorials include:

• Building a File Manager - Part 1, Part 2
• Data Access Benchmarks
• Security Forms using the GD Library
• Snippet: A Better PHP Highlighter

There's a few others as well (including one CSS and two webserver installation tutorials), making this page a good one to keep in the bookmarks for the future. All of the tutorials include all of the source code/information that you'll need for the application.