http://tech.yahoo.com/blogs/null/34884
While laptop chips have become better and better at saving power, other changes, like more powerful laptop graphics cards, faster hard drives, and Windows Vista, have erased many of those gains.
So, you'll need to take it upon yourself to improve your laptop's battery life if you really want to go the extra mile. And while that can be a confusing and tricky process, this blog post offers some helpful advice so you don't have to go it alone.
Add more RAM - More RAM means the computer will access the hard drive less frequently, and the hard drive uses much more power than your RAM sticks.
Dim your screen - Those big, "ultra-bright" displays really suck down the power. Dimming your screen just 20 percent can add a good chunk of time to your battery life.
Unplug external devices - Anything plugged in via USB, FireWire, or PC Card/ExpressCard draws power from your computer. Yes, even your mouse. And of course, turn off your Wi-Fi radio when you don't need it.
Minimize CD/DVD use - Optical drives are probably the worst offender on your notebook when it comes to battery use. Unless you're watching a movie, don't even leave a disc in the optical drive, as Windows loves to occasionally read it, just to check on things...
The post doesn't exactly mention it, but don't forget about the Power Options control panel in Windows, which will let you manage hard drive auto-spin-down, screen brightness, and other settings in one central location. It's a great first place to start... then check out Friedbeef's 11 other tips!