http://www.zilvia.net/f/login.php?do=logout&u=XXXX
Copy that, paste into address bar, enter your usernumber where the X's are, hit enter.
You can find your usernumber by viewing your public profile.
Example:
http://www.zilvia.net/f/member.php?userid=1000
Logout string would be:
http://www.zilvia.net/f/login.php?do=logout&u=1000
Easy as pie.