Never heard this mentioned over here so I thought I'd post it.
Pangolin produce a FREE application that allows you to instantly dim your screen for laser displays so you can better see the display rather than beign dazzled by the brightness of the monitor (or having to mess around with monitor settings).
Its called Pangobright and whats more it dims EVERY window on the PC not just Pangolin software so no matter what other software you might be running, there will be no nasty sudden bright changes between windows.
It works by sitting in the system tray as an icon and then allowing you to adjust monitor brightness with a simple slider.
I've copied this off the Pangobright forum its a simple animation showing how the slider works:
It can also work across multiple monitors and allow individual adjustment of each.
It is downloadable from here:
http://www.pangobright.com/