I needed a quick and easy fix. I found one, it’s called Shades. It’s free. From the delevopers site;

Shades is a FREE utility for controlling the brightness of your screen. It runs in the background providing always-available fine-grained control over the brightness of your display via a slick Mac-like interface.

Shades installs into the System Preferences window and it’s very easy to use. If you run into any trouble/questions there’s a useful FAQ.

The other app is Menu Eclipse (no direct link, find it under ‘Software’), it goes nicely together with Shades. From the developers site;

Save your constant menu pixels from getting burned into your screen!
Gain better focus on your work & play, and away from the menu bar!

Its single purpose is to dim the top menu bar in Leopard. The effect is pleasant when watching a movie but I’ve found I use it all the time at about 40% ‘strength’. When you hover over the menu bar the effect goes away. Nice. Oh, and did I mention it’s free? It is.