So I'm a long time lurker, first time poster bla bla bla... I'm trying to figure out the best way to balance screen brightness and battery life. Twice a week I have a university class that requires me to work on my MBP (SR 2.4Ghz, 4gig ram) for three to four hours, and I need to squeeze every ounce of power out of this machine as possible. But I am having a hard time finding what brightness level yields the best brightness to battery ratio. I have noticed at some point maybe midway in the spectrum there does I don't seem to be gaining any more efficiency than if I was at a higher brightness. Has anyone else noticed this? Where do you set your brightness when you are not "plugged in"?