Sketch type renderings in blender

Blender can be used to generate sketch type renderings also.For this  freestyle render has to be used from within blender.This is not included in the official version of blender a freestyle build can be downloaded from  http://graphicall.org.
I tried freestyle in one of my models and the results were quite good.This is one of my initial renderings with minimal settings.Frestyle can be used with blender internal renderer.

Rough render with freestyle

while using freestyle build one has to enable freestyle in post processing in the render tab.also the settings for freestyle are given in the screenshots