Last time I was at UNT you could use the linux machines directly but I know they changed it shortly after I left. They do provide an Xserver for you though so it's more or less the same as sitting in front of those machines still.

Also there are various specialized labs on campus that you'll gain access to if you take the appropriate classes (or give decent reasons for access to the lab maintainers) that have linux such as the CoPS lab. I believe Rada even has a linux based lab for computer linguistic learning. She did when I left anyhow.

So the linux computers that you can sit down at are there they're just not readily advertised.

Something I'm thinking of doing when I've got little ones running around is putting their pc's behind a special gateway. This way I can block off specific websites, ports, etc for their subnet. Maybe even a way to disable/enable the internet depending on the time of day. (chron jobs maybe?) You could also log everything because all the net traffic would be comming over one line. I know it isn't the perfect answer but it seems better and cheaper if using linux than software solutions. If I had it logging some stuff I'd just do random checks of the logs for stuff that wasn't allowed. This would all be pretty invisible to the children too. Keep the gateway under lock and key and I'd consider my self pretty lucky if my kid was 1337 enough to hack my box.