In Fedora 16 there is no shutdown option by deafult..We have to logout first and then need to shutdown from the gdm.
This can be tweaked in two ways
First easy way:
By pressing “Alt” key the suspend changes to poweroff
And if we need a permanent poweroff button we must install these two as root user
yum install gnome-tweak-tool
yum install gnome-shell-extensions-alternative-status-menu
After installation you will get an advanced setting menu..Enable alternative status menu in it…Then you will get poweroff..
Happy Hacking 🙂