I got a new Thinkpad X201 last week with the 6 cell battery, which is advertised to work for 5 hours. I installed Ubuntu Maverick on this machine right away. My battery life is only around 2 hours. Is this because the Thinkpad's battery power management only works well under Windows? Or can I change some configuration to make my battery last longer under Ubuntu?
You could try installing powertop, it is a console application.
It will monitor your machine for a few seconds, then tell you what is likely causing the power drain. You can then use it to try and make your machine more efficient.
Hope this helps.