Brandon Savage has a new post to his site today showing you how to compile and install PHP 5.5, the next major upcoming release for the language (in RC status as of the time of this post though).
There's always a lag behind new releases of PHP and releases of packages for operating systems such as Ubuntu. This lag time means that you could be kept from upgrading to the latest and greatest PHP for a year or more, unless you use an outside repository like Dotdeb. [...] Instead, I roll my own version of PHP. It's simple and easy to do, and something that any developer can do. Here's my instructions for doing so on a fresh Ubuntu installation.
He gives a reason or two why you might want to "roll your own" installation and helps you get the environment prepared via some "aptitude" install commands for supporting software. Commands are included for installing needed dependencies, configuring/building PHP and updating Apache to use this new install. He finishes it up with a few smaller things to do like making the php.ini and enabling the Zend opcode caching extension.