Can't find shutdown applet on the panel or in the dropdown box on my Ubuntu 10.04.
Currently I'm using the following command to power off my PC.
I want to have my applet back.
Adding the Indicator Applet back to the panel is the "right" solution, however if for some reason that doesn't work for you, this blog post describes how to create your own shutdown, reboot & hibernate with one click applet.
Right-click a blank area of the panel and click "Add to panel."
Then drag the "Indicator Applet Sessions" item to the panel.