Mac users interested in Gfxcardstatus os x 10.6.8 generally download:
Control the consumption of GPU output in your system when running demanding programs by viewing the status of your processing unit via the application. It features an option to identify and switch between multiple GPUs when performing multiple tasks.
gfxCardStatus is a menu bar application that keeps track of which graphics card your unibody, dual-GPU MacBook Pro is using at any given time, and allows you to switch between them on demand.
gfxCardStatus uses Sparkle, so you're always running the latest and greatest version.
switchGPU makes your Mac automatically use the integrated GPU when you login. The script will start gfxCardStatus three times consecutively to address the problem of the selection (which GPU) not being preserved immediately. switchGPU uses a version of gfxCardStatus that accepts the mode you want to start the program in as a command line parameter.