Timed logouts and temporarily disabling accounts


I'm looking for some software that will log out a user have a set amount of time. If I give the kids 1 hour a day on the computer or 3 hours a week then the program will log them out at the end of that time and not allow them to log back in.

Also, on a related note, if the kids are grounded from playing on the computer for a week I'd like an easy way to disable their login for a week and either have the computer reenable it or allow me to reenable it.

Theres probably a way to do the autologout using quotas but I don't know it...

To disable the account, you could just change their password. Maybe setting their shell to dev/null would work too.
Changing the password won't work because I won't know the password to change it back to when they will be allowed back on.

Humm.... If you had REALBasic.... you could write an application that has a timer opbject set for whatever, and once the time specified was reached, it could then shell a command to logoff ( have to find what that was if exist ) you can restart the computer via "sudo reboot" but when you sudo it ask for your admin password, and this would not work when sending shell commands from your REALBasic app... but if there were as logoff command that did not require sudo ... your good to go using RB....

I'll snif around this, if I find it, I might just make an app real quick for this... something with visiable disabled, and put into your startup items folder .. should work ?