If you havent allready seen whats on the WIKIU/P acknex/acknex might help explain a little more. I know nothing really of shaders myself and am deffinately interested in what some of the others have to say. However I know they can be used for things like bump mapping,toon shaders, fur shaders and a few other things. It can really help to add atmosphere and quality to your levels,models ect if done right. Im about to attempt bump mapping yet again so wish me luck