I've got a laptop with the Intel GMA 4500 chipset, and my Ubuntu system is using the i915 driver.

I've gone through a few different versions of Ubuntu, and other linux distro's, each one unable to control the brightness. This is obviously eating up my battery life, since the screen is at a constant 100% brightness, when I usually use about 35% brightness.

I've gone through gnome panel widgets to try and change it, the /proc/whatever method (brightness settings in a file)... nothing seems to change the brightness.

What should I try doing to get my brightness control? I don't mind working at this quite a bit, since this is effectively killing about half of my battery life.