Kalternatives

I found this cool package today:

sudo apt-get install kalternatives

From the package info:

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.

Some of the options I wanted to customise:

desktop-splash
usplash-artwork (usplash-theme)
x-terminal-emulator
x-window-manager
x-www-browser