On the Phantom Reference blog there's a post that looks at the integration between NetBeans and PHP via a plugin.

Do you know that you can use NetBeans to build web applications using PHP? PHP plug-in is an extension to the NetBeans IDE that enables you to perform web based development on NetBeans. While there are several PHP IDEs available in the market today, NetBeans PHP plug-in offers the same functionalities offered by other IDEs and then much more. Here is a short note to quickly get you started with NetBeans PHP plug-in in Solaris.

The instructions are pretty adaptable for any OS out there, but you will need a build of NetBeans 6.1 as well as an Apache/PHP instance to configure. The setup is complete with screenshots as well as an example of making a script and running it right there in the application (no web server needed).