If you're interested in the deployment of PHP applications, you'd do well to check out a series of articles Kevin Schroeder has posted to his blog talking about different methods for moving your site out when it's ready for the world to see.

His articles cover:

• Things to take into consideration when creating a deployment process
• Using rsync
• Integration of source code management
• Creating PEAR packages
• Making installable packages (like yum, RPM, etc)

This last option, while a bit more difficult than some of the others, seems to becoming more and more popular as a self-contained, easy to deploy method that's very controllable.