Give it a shot... Updated.
Next... try to get brightness settings to work inside of ubuntu.. that needs to be changed in the kernel..
otherwise you can always do
echo "0-255" > /sys/class/leds/lcd-backlight/brightness
to set the screen brightness. 0-255 is a range of values you should use.
0 will turn off the backlight
255 is full birghtness
and of couse.. service powerd stop while the screen is on will stop powerd.