Many of the individual applications that you previously saw in the system settings you saw in Natty (11.04) have now been gathered together under the banner of the
Thus to launch the Power Manager from the command line you need to run
The way I found this was to run
gnome-control-center - double click on the setting you want and then type
ps -ef | grep gnome-control-center to see what the process is being run e.g.
ps -ef | grep gnome-control-center
dad 2158 1592 0 21:07 ? 00:00:00 gnome-control-center power