I tried this before and I found Slitaz actually traps and forwards the power button event to a script for processing. There is also a package called linux-acpi along with acpid in the repos btw, so you may want to install that too.

Now in Slitaz the event works like this: /etc/acpi/events/button.conf catches all button related events (The keyboard's power, sleep or wake buttons and the PC's power button). It then forwards it to the /etc/acpi/button.sh script for processing.

How to make it work after that is anybody's guess - I tried the suggestions @ http://wiki.archlinux.org/index.php/Shutdown_Pressing_Power_Button without success too :( - Hope you have better luck than me

I installed both the packages, and tail -f /var/log/messages shows that the acpid daemon is running, however pressing the power button evokes no response. Usually if I press other 'special' keys, /var/log/messages will atleast acknowledge the key press.

Am I missing something?