Auto logout Console user from KDE

[alaric at angeldustrial.com]

Hi, I have a old 266 running Red hat Fedora that we set up as a community
computer where my roommates can log on and check email in the common area of
the house. Unfortunately my roommates are extremely bad at logging out! I
ran a few goggle searches and found the TMOUT=  command that lets me timeout
a Bash session but that doesn't logout the X session. Is there a similar
command that would let me time out a user after they have been idle after X
amount of time?

Thanks!

-Alaric