Lifehacker recently found a nice article written on the Friedbeef’s Tech blog which gives 15 tips on how to get the best longevity out of your laptop’s battery. Here are a few of the tips which I find the most helpful:

• Defrag regularly - if your disk is defragmented the disk will be more energy efficient
• Dim your screen - the size of your computer’s screen, and how dim or well-lit it is has a big influence on your battery life. If you’re looking for a laptop that will give you a great battery life, don’t look for those laptops with big screens.
• Cut down on programs running in the background - the more programs you have running, specially those that access or record data on to your disk, the less battery life you will have
• Cut down external devices - USB devices, specially those with batteries that are charged via USB (like iPods and other DAPs), and Wifi or similar wireless network devices/protocols all consume a lot of energy.
• Run off a hard drive rather than CD/DVD - running things off of CD/DVDs consumes a lot of energy, much more than the energy that a Hard Drive requires.
• Go easy on the PC demands - “Passive activities like email and word processing consume much less power than gaming or playing a DVD. If you’ve got a single battery charge - pick your priorities wisely.”

You can find the full list in the original article, but these tips above should be enough to get you “started”.