Though I still prefer the elegant command line option, the GUI feature does make it more usable.
It is available through package manager in ubuntu 9.10.
sudo apt-get install gshutdown
You can add it to your panel(from Applications > Accessories) and run it as root.
The below image are my settings from its icon properties:
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Its auto detect features did not work for me so I manually defined commands
for shutdown and reboot.
My custom command for shutdown is as below:
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