Due to the popularity (and age) of his previous post about compiling PHP 5.3 on Snow Leopard (OS X), Sean Coates has written an updated post showing some of the changes to the process that the updated OS version has brought with it.
I've been meaning to post instructions on how to compile PHP for Snow Leopard since last summer when I picked up the DVD, but hadn't found the time or opportunity to build PHP from a completely fresh start, until a few weeks ago. This time, I took notes on how to reliably compile PHP and Apache from scratch on this system.
He's made a six step process that includes installing Xcode, Homebrew, your own version of iconv, support for whatever dependencies you might still need and, of course, Apache/PHP.