In versions of Android OS before Ice-cream sandwich, there used to be a nifty tweak to increase the brightness of the screen by swiping left-to-right or right-to-left through the top Notification bar in the home screen. ( displayed in Red color)
But in ICS, this feature seems to be removed from the Samsung Android phones. In search for a similar functionality, I came across a nifty little app Display Brightness ( click link to go to Google Play app )!
It creates a small hidden section in the top in the notification bar and you can just swipe your finger on the top notification bar brightness section to change brightness. ( section in Blue color)
Hope you would like the suggestion ! :)