If you are an intensive Windows user, you may like to check out this freeware utility Vista Battery Saver. This tiny program claims to save up to 70% of your battery by disabling some Windows features.
Vista Battery Saver
Running in task bar with a private workset of 5.5M and 0% CPU, it will do all the work for you, by enabling and disabling customizable features when power source changes or battery power falls under a certain percentage.
It automatically deactivates Windows Aero and the Windows Sidebar when your laptop runs on battery power, in an attempt to extend battery life.
You can also configure the program to automatically turn off Aero or the Sidebar when your batter level drops below a limit that you set.
Download Vista Battery Saver from Codeplex.