I like using OS X's built-in packages where possible, but unfortunately Apple is way behind with their PHP package, having it locked on 5.3.15. In the past I've seen people use tools like Mamp, or Xampp to provide this for them, but frankly I'm not a big fan of these tools.
Homebrew provides a solution. Homebrew is OS X missing package manager, and it's an absolute great tool to work with. Getting started with it is a bit harder, as there's a few bigger dependencies you need, such as an up-to-date XCode installation. Once you've installed homebrew, it's a matter of running the following commands: