If you want to talk about great PHP scripts then you need to check out phpXplorer.
From the website:
phpXplorer is an open source file management system written in PHP. It enables you to work on a remote file system through a web browser. By default it has got dialogs for editing HTML, PHP, image, Apache, compressed and email files. Its modular design makes it easy to build your own filetypes, property sheets, views and themes. phpXplorers permission manager enables you to restrict the access to the shared file system for multiple users in a detailed way.
I’ve been looking for something like this to setup a more useful file hosting site for my personal use for sometime. This looks to me to be the answer.
I could see this as a perfect way to setup a file sharing site for family and friends when you don’t want to have to explain how to use ftp. The security allows you to share only the directories that you wish while not opening up your entire system to everyone you grant access.