I’m still trying to tame my Ubuntu 10.04; today I wished to disable two Gnome features that I’ve never used: fast user switching and guest access.

In order to do that you need to install gconf-editor, if you havn’t done that already; by using it you can then enable the following variable:

/desktop/gnome/lockdown/disable_user_switching

By the way, under /desktop/gnome/lockdown there are some other variables that could be used to achieve some kind of kiosk configuration, even if they aren’t too many at all.

I found the information in this post of ubuntuforums.org; thank you guys!