On the JSLabs blog today, there's a quick look at one somewhat underused PHP tools out there that could help tremendously in the long run and do something that most developers run screaming from - writing documentation. They talk about the wonderful phpDocumentor package.
Documentation is a very important part of development. It will not only allow you to come back to an application or piece of code in the future with ease, but also help future coders (in the open source community or at your job, etc) that may be utilizing your source code.
They look briefly at it's features, the installation process, and how you can start documenting code right off the bat with the help of examples and a sample phpdoc statement they provide.