Laptop power button press again to cancel shutdown?

We've all done it, you come back to your laptop and press the power button.. forgetting it was already on! So then it shutsdown, and there is no way to correct the mistake.

It would be pretty easy for Ubuntu to connect the button as a toggler, so if pressing again while in the shutdown runlevel, it toggles and goes back into multi-user and X login (level 5 as I recall)