Hey there MacRumors! I have just released my first mac app, ScreenDimmer. It gives you fine grained control over your brightness (though the use of a slider), but also allows you to selectively dim certain monitors in your setup instead of dimming all at once. This is great for watching movies or playing games, tasks where you want your focus to be on one screen rather then two (or three or more). You can download it here. If you have any questions or feedback, please do not hesitate to contact me here or at my website. Thanks!