[FFZERO]

To dynamically change your clock speed, you can run the following command:

sudo dpkg-reconfigure gnome-applets

"Right-Click>add to panel" on the panel and select cpu frequency scaling monitor. You can change the clock speed by left-clicking on this applets. I have done this myself many things when I was using ubuntu without any problem. The disclaimer only warn you that you have the power to change the clock speed without root/sudo permission.

You can rerun the command again if you feel uneasy about what its telling you to do.

However, to achieve only 3 hour with a 9-cell seen really off. Have you drain the battery to 3 hour or only look at the battery meter? The battery meter can sometime be off (like windows) and the only real way of knowing how much battery life you have under linux is to try doing a drain test. For my m1330, the battery meter tells me I only have 3 hrs but in reality, I mange to get 3:30 (with little to 20 minutes left). I had the brightness on level 3, clock speed - powersave, and Ethernet cable plug in with wifi/bluetooth off. I also am not using laptop-mode (disable the utility).

By default, distro such as Ubuntu have your cpu default to ondemand for anyone wondering.