Now that MacPorts 1.7.x is finally out I thought I'd re-new my MacPorts installation and document the installation procedure for a basic PHP 5 and Apache 2 setup. Let me know if anything below fails but it worked fine for me today (20 December 2008).
Pre-requisites
Read the installing MacPorts guide and get all the pre-requisites installed, such as X11, X11User/SDK, XCode.