Kalternatives offers a GUI to configure the alternative systems (a system that allows you to select one alternative file for many in the filesystem). Kalternatives is available as KDE configuration module, integrated by default into KDE's System Settings.
This is an advanced GUI of the update-alternatives program shipped with dpkg.
It's handy and it's integrated into the System Settings application. However, it requres (and does not prompt for) superuser permissions in order to make changes. I had to do "gksu systemsettings" in order to edit anything with it.