Does it have Optimus, i.e. two graphics chips? Which chip do you use more often? I keep my T410 exclusively running on the power-hungry nVidia chip and don't get more than 2hrs of battery life.
It does have Optimus and the battery life is about where yours is - maybe 2.5 hours.
I'm running the nVidia chip exclusively, but when I get around to it, I'll probably switch, as I'm running an openbox desktop that just doesn't need that kind of graphics acceleration. I have yet to figure out a painless way of switching between the two, but that's probably because I haven't really worked on it much.
There's no current way to switch painlessly, but there is something that makes it slightly nicer than having to restart all of your programs. Check out Bumblebee [1]. It does it by running two X servers, one for the lower power system and another for the NVIDIA binary blob and plays with environment variables to get things working. Then it takes the NVIDIA server and copies the images over to the slower card. In a round about way it's what windows systems do for it, but not quite as sane and not quite as performant. There's been some work to create the sharing needed so that drivers can share the buffers directly and eventually there won't need to be the second X server. However this also depends on if that work either gets its license changed or NVIDIA GPLs the kernel bits to their driver.
I have only ATI cards and the difference between open source driver and proprietary driver is world apart. With radeon I have +2 hours, with fglrx it's ~4 hours.
