Ok, more tech tips. On the late model (2008-2012) MacBook Pros, there are two graphics cards. If you want to see if this is the case for yours, go to the Apple Menu -> About this Mac -> More Info (and then System Report for mine). Under the Graphics / Displays tab, you will note that there are two listed.
For me, these are an AMD Radeon HD 6770M, and an Intel HD Graphics 3000. The Intel card is ‘integrated’, while the AMD card is ‘discrete’ (i.e., attached). When you need a higher-power graphics card, the Mac is supposed to automatically switch to the more power-hungry one. There is a toggle for this in System Preferences, under Energy Saver. But….
But the switcher kind of sucks, and most of what you are using your computer for does not require the discrete card. Plus, when you are on the go, or on the sofa, you often want more battery than higher graphics.
Sooooo, a college kid named Cody Krieger wrote a small piece of software that allows you to control this switching. I have mine set so that when it is running on battery power, it runs ‘integrated’, and when it is plugged in, it runs ‘dynamically.’
The upshot of this is that I am getting literally hours more battery life out of my laptop than I used to get.
There is an Ars Technica article about the hows and whys of this little piece of software. Highly recommend.