The International PHP Conference 2002 was a huge success, and there were tons of talks that came out of it, including one by Hartmut Holzgraefe that talks about the benefits of having a CVS system for you and your other fellow developers. (don't worry, the name may be in German, but the PDF is in english).

He starts off with a discussion of what CVS is good for and why you should use it in your development (trust me, it's a good thing). He then moves into some of the tools that you can use to access a CVS repository. While the PHP tools for getting files from the repository are still somewhat lacking, there are several C-based tools that can more than fill in the gaps.

He also briefly mentions documentation - how programmer-written documentation is great, but only for other programmers. There are some utilities out there that can take some of these comments (correctly formatted, of course) and make them into something an end-user can use.

Thanks to Ewald for the link.