For those of you with Windows Vista, there is a new technique that can boost your battery life by up to twenty minutes.  You may have heard of ReadyBoost which uses either a USB flash drive or memory card to supplement your PCs memory.  Test have shown that you can get an increase of up to twenty minutes of battery life by taking advantage of ReadyBoost - it keeps your machine from having to use the harddrive and therefore saves battery life.  Try it out!