Eddie made rotoscope in Blender here the link
http://blender-an.org/scontent/animation.php
Wow this is exactly what I am wanting to do. I am anxious to learn how this was done. I was thinking I would have to film a person, then frame by frame move the verts to match the real person.
Lactose: You have compositing filters that could do an edge detect on your film, and produce the outline. See Kirsch filter in wiki.