There's been times that I forget to log off my computer at work. I do have the ability to VPN into the office and ssh into my box. From there I can log myself out:
Find out which terminal I forgot to log myself out of:
# who
Kill the terminal I'm logged in at, if I am logged in at pts/0, then I would issue the following command:
# skill -KILL pts/0
To log out users based on user name:
# skill -KILL -u paulus