Newer video cards have new extensions to support gamma-correction on Textures & FrameBuffers, and in a new Gamasutra article from David Rosen he shows the benefits and gives information on how to enable this effectively-free feature.
The lighting equations used for computer graphics are all based on physics, and thus assume that brightness 1.0 emits twice as many photons as brightness 0.5. However, on a computer screen, this assumption is not correct. Until very recently, there was nothing to be done about this, so we just lived with lighting that is physically incorrect. However, modern graphics cards have tools to support gamma-correct lighting, which you can see below on the right.
