gfxCardStatus is an open-source menu bar application that keeps track of which graphics card your 2010 MacBook Pro is using at any given time, and allows you to switch between them manually.
Simple, clean "i" and "n" icons that signify Intel HD Graphics, and NVIDIA GeForce GT 330M graphics, respectively
Automatically updates when the GPU switches, in real time
Allows you to manually switch GPUs on demand!
Dependent process list - see which applications are currently using the 330M, if it's the active GPU!
Growl support - so you know right when the GPU switches
Tiny footprint - doesn't sit in your menu bar and hog RAM or CPU cycles
Automatic application updating - checks for, downloads and installs new versions of gfxCardStatus automatically!
Mac OS X 10.6
Mac OS X 10.7
Mac OS X 10.5
||Only for 2010 and 2011 MacBook Pros with Intel Core i5/i7 processors.