[machem]

Well, I just figured out where the ambient light sensors are for the display/keyboard on the 15" 'Book: top of the speakers. I set both of my hands over the speakers (I was actually trying to measure the heat output for sh1ts and giggles), and my screen darkened up. I found that you need to cover both areas to darken the screen, but strangely, removing one hand doesn't bring it back up.

This can obviously provide minutes, if not seconds of fun!

[pknoll]

The sensors interact. You also cannot darken the screen (or activate the backlight) by covering only one sensor - both have to "see" the new light level to trigger a response.

This is something I didn't expect to be done so well, but then I'm new to Apple hardware, and getting used to being pleasantly surprised. =)