Set KDE as default in Ubuntu?

[Alan Dayley]

I installed Ubuntu 8.04 on a system because I don't currently have a
Kubuntu 8.04 CD.  No big problems encountered.  I then installed the
kubuntu-desktop meta-package to get the KDE desktop installed.  Again,
no problems.  I set the login manager to KDM. Cool.

Now I want to set KDE as the default desktop.  I am about to setup
several users in the system and they are all used to KDE.  It's not a
big deal to configure KDE as each user's individual default but I'd
rather use some system-wide setting to default it.  Does anyone know
where such a setting would be?

Alan