If you run Vista on a laptop, stop whatever you’re doing right now (which I guess is reading this), and go get the Vista Battery Saver to improve laptop battery life on Vista. It automatically switches your power plan when you plug in to or unplug from AC power. It will also disable the Aero Glass user interface and disable the Sidebar when you switch to battery (it turns them back on when you plug in again).
This handy little utility runs in the background with basically no CPU overhead (it uses a little bit of memory of course).
The ASUS utility Power4Gear works much better then this pos.