One of the benefits of KDE is that is has the the most powerful IO interface of any desktop environment I have ever seen. KIO allows for a pluggable interface to outside resources in a simple and powerful way. The best part about it is that is works system wide. For example, long before Windows was working on a DB file system; a enterprising KDE developer had created kio_sql. This allows every KDE application to have access to any database as if it were just part of the file system. You can open table data just like you open a test file.
One very cool KIO module is kio-locate. Locate is a system wide indexer for Unix OSes. On the command line you can type “locate bob” and it will return every file with the name bob in it INSTANTLY. Want to open your websites index.html file but you don’t remember where it is? With kio-locate you simply start your web development environment, click file->open… and in the file selection dialog type locate:index.html… and you will see every file named index.html that you have access to on the system. Its like having a file name meta data search available in every KDE application. Check out this screeny to get an idea of what I mean.
There are literally dozens of KIO interfaces for everything you can imagine. kio_rar (for access to your rar files without unrar’ing them), kio_burn (gives every KDE application drag-&-drop file burning capabilities), kio-sword (browse the bible like its a file system), and the one I use most often ipodslave (aka: kio-ipod), which gives all of my KDE applications access to my ipod (i.e. any music player can play from it, and all applications can save files to it.)