When you install KDE 3.x (Just the desktop environment not kubuntu, this can be done by typing: sudo apt-get install kde) On first boot the system shows an assistant that ask you to make a few tweaks for the interface and this could be applied to Ubuntu.

While booting gnome desktop Show a Welcome screen that tells the user to make the last configuration details:

1- Shows you options for your interface according the user's preferences:

1.1) Option one: Windows (similar interface) one bottom panel with gnome-main menu and trash on the desktop and windows' keyboard shortcuts.

1.2) Ubuntu Default Installation: Top-Bottom panels interface that we're used to and Ubuntu's default keyboard shortcuts.


2- Ask the user if he/she wants to install any proprietary drivers for the computer's hardware and configure your wireless connection.

3- Let the user to keep that theme or change it with alternative versions of the default, also ask the user if he/she wants system sound notifications and Desktop effects.

This would be really user-friendly and help the user to have a place to start using Ubuntu with just 3 simple steps.

Here I show an example of welcome screen:

http://upload.wikimedia.org/wikipedia/en/0/0c/Opensuse_10.3_first-boot.png

Here I attach the Fedora project wiki:

http://fedoraproject.org/wiki/FirstBoot