I just created an account for my son on my laptop, running Edubuntu 6.06. No problems there - it's a reasonably intuitive process. However, when I tried to find a new login screen for him to log in, I could not; I tried system>administration and generally peered in all the menus when that didn't work.
I've since been told that I should have tried System>Quit which has a 'Switch User' option. This was not obvious at all; because I did not want to quit, I didn't try that. I've also since noticed that hovering over the quit option displays a tooltip reading "Log off, switch user, lock screen or power down computer", but again, as I was quite sure I did not want to quit, I did not notice that earlier. In fact, the place where I should have tried was the one place I was certain I did not want!
Perhaps a better place for this would be just above the quit option?
Part of the problem seems to be that "Quit" just isn't a great name for this. Out of six options I see on my laptop (log out, lock screen, switch user, suspend, restart, shut down), only three are unambiguously quit-type options (log out, restart, shut down), lock screen and suspend are on the edge, and switch user is explicitly not quitting, only letting somebody else use the machine for a while. To many people, "quit" is a less jargonish synonym for "log out".