The Freestyle Render is a Non-Photo Realistic (NPR) rendering system currently being developed for blender. It is not yet part of the official Blender distribution.
Book pages turning, with Blender Freestyle. See the video first. And read the tutorial (PDF). Note: this tutorial if for an old development version of Blender Freestyle. Many things are likely to have changed. The tutorial is nonetheless well written and well presented and is worth a read!