Adam Kinney did a pretty neat port of a flash application that creates an effect that gives an image like it was torn and crumpled up in Silverlight using the WriteableBitmapEx.
Blitting is the act of blending multiple images together. More about the BLIT operation can be found at Wikipedia.
Adam used the Blit method with different blend modes to achieve the effect from the standard image. With masking, alpha blending, and the multiply mode combined with a few masks and textures, he was able start with a standard image and give it that “pulled out of my pocket” effect.
The WriteableBitmapEx team over at http://writeablebitmapex.codeplex.com/ really did a great job with their library too!