I don't know a thing about Blender, but in 3dsMax you could accomplish this with a simple bump map texture; a grey scale image where lights are the raised areas and the darks are the recessed areas. You can then increase or decrease the intensity of the illusion it being a 3 dimensional surface. You must be able to do something like this in blender. I imagine you could get a pretty decent texture with just a bit of noise.
The actual renders were only like 10 minutes a piece, relatively low quality so there's some noise. I had a render going last night, took 3 hours, not on the home computer though.