Inverting the Mac screen with a keystroke
I know only a thimbleful of OS hacks for any platform and I'm often the last on the block to learn that some arcane combination of keypresses and mouse clicks will change my laptop into an ad hoc defibrillator or something. (This would actually be useful, I think.)
I was delighted to find out the control-option-apple-8 will desaturate and invert the display on my PowerBook. Ostensibly it exists to help make displays usable in direct sunlight.
Probably, but if I turn on the iTunes Visualizer after... I'm talkin' a well-pimped distressed animation!