I've set my screen brightness to about 50%. This works fine for me, except that the setting seems to be ignored when it's charging: then it's 100%. I've got a desktop charging stand on my bedside table, and this is exactly the place where I don't need maximum brightness!
How can I make my iPhone respect the brightness setting even when charging?
This is an iPhone 4 (iOS 4.1) but I noticed the same with the iPhone 3G (iOS 3.1.3).