There are tons of widgets and apps available in Android market for screen brightness control. Though, Brightness Motion is the only app available (in lite and full version) which lets you control the screen brightness with motion gestures. Moving on, of course it will save it battery over time by gaining control over your screen brightness settings.
After installing the app from Market, launch and tap Start Motion Detection Service to gain control over motion gestures and screen controls. And simply move your device to the right to raise or increase brightness and to the left to decrease it.
The motion gesture controls becomes very helpful when playing games. There is no need to leave the app anymore, simply do the gesture and the control can be seen. Brightness change speed can vary from device to device. Tests were good when tried on Nexus S wih Pro Evolution Soccer, and Angry Birds.
Controls include start / stop service, start on boot, motion sensibility, interval detection, haptic feedback, vibration duration and brightness control.
– search on Market