Red Hat had a feature useful to me at the present time. There was an account, generally called "shutdown", and when you logged in with the account, the system shut down.

In my specific case, I have Ubuntu Server running in a VM on my local system. The VM is running a web app, and when I'm done doing work, I want to shut down the VM. Unfortunately, I can't install VMware tools to get the "power button" based shutdown. Currently I login then sudo shutdown -h now, then type my password again, and things shutdown. Really, it's getting annoying all that waiting around and typing things.

How do I replicate the "shutdown account" functionality in Ubuntu?

A related question, were there any security gotchas that motivated people to stop using this kind of account?