On the Filter Forge page in this blog, I link to a beautiful image showing its use to create a snakeskin texture for a 3D model. But, Filter Forge is also an excellent source for filters to alter your images in a multitude of ways.
Here are two images of Eepo, the elfin warrior, at her cabin.
One is the original. For the other, I used Filter Forge to turn it into a watercolor!