I should really write this in a seperate PHP-post, but here it goes:

I just added the following packages to the repository:
php53 (tested)
php53-gtk2 (tested)
php53-mysql
php53-sqlite
php53-gd
php53-mbstring
php53-xml
php53-dev

After installing php53 and php53-gtk2, you can run PHP-scripts like this:
phpgtk myscript.php

Or without Gtk-support:
php myscript.php