This tutorial will show you the basics on how to use .glade files from within your PHP-Gtk2 application.
Glade2 is a User Interface Designer, allowing you to create Gtk2 application with just your mouse and no programming. The results of your work are saved in a .glade file and can be loaded into your PHP-Gtk2 application easily.
Creating the user interface with Glade saves a lot of time, especially in large projects and even gives you the ability to divide the work: The interface designer person designes the GUI with Glade (and doesn't need to know anything about programming) and you can concentrate on programming rather than bother your mind with GUI accessibility tasks.