1. Applications -> Accessories -> Terminal
2. sudo dpkg-reconfigure gnome-applets
3. Select Yes when prompted
4. Right click on the top panel and select Add to panel..
5. Select CPU Freequency Scaling Monitor from the list and click Add
6. Left click on the new applet and select Powersave
While I am unsure what effect this will have on the battery in Ubuntu other operating systems have gotten a 40 minuet boost with CPU freequency enabled. You may also want to get a 9 cell battery for this laptop given its short battery life. From my understanding this is available for the S37S.