Enable Hibernate option on Fedora 16

• yum install gnome-tweak-tool
• yum install gnome-shell-extensions-alternative-status-menu
• Log Out and Log in back
• Launch the Gnome-tweak-tool and from Shell Extensions tab switch the alternative-status-menu extension to ON
  
  
  Courtesy of --
  http://ask.fedoraproject.org/question/478/edit-power-menu