Instant shutdown by pressing the power button (Ubuntu)

http://askubuntu.com/questions/86376/how-to-specify-power-button-to-do-a-shutdown-h-now-instead-of-graphical-shutd

That's simple enough. When you press the power button a ACPI event triggers the script at /etc/acpi/powerbtn.sh.

You can edit that to just run shutdown -h now as the first thing so it looks like:

#!/bin/sh

# /etc/acpi/powerbtn.sh

# Initiates a shutdown when the power putton has been

# pressed.

/sbin/shutdown -h now "Power button pressed"

exit 0

# leave the old code below (in case you want to revert!)