02 Xphone 2 brightness control

[Guest evilution]

Hi guys - is there any way I can lower the display's default brightness - via some menu option that I seem to keep missing as I go through the settings or by a program or just by editing some sort of registry value?

On another question - I dont know if my o2's battery is fluky. For one thing I can only get about 4hours continuous usage on it ... any ideas to this? Im using it to read e-books and after 4hours it starts to drop to about 20% + .. im figuring lowering the brightness will let me read a wee bit longer :)