The powertop utility from INTEL has been very interesting to use. Unfortunately, I'm quite pissed off.
“gnome-power-manager doesn't dim the backlight to save power it actually just changes the colour of the pixels on the screen”
Err no. It never has and never will. It actually dims the backlight on all the hardware I have tested it on.
Dimming to 30% when idle saves me about 1-3W of power on all three laptops I own. That's a X60 (ibm+intel), n100 (lenovo+nvidia) and a A10 (toshiba+old-intel).
For the X60, g-p-m calls HAL, which writes to the thinkpad_acpi controlled backlight class. This then writes a value into the embedded controller address space (or issues a CMOS command) which changes the hardware backlight brightness.
Really impressive graph by the way – but what crack are you smoking?