Extruding stencil volumes in hardware

There was an interesting little article on FlipCode about how to extrude stencil shadow volumes partially in hardware without having to use a vertex shader. I think it's a pretty neat trick. It involves, however, having to create a real silhouette, which is not what I'm currently doing (just a "lazy" silhouette created by duplicating every edge in a mesh and having a vertex shader extrude the neccessary edges).

Have a look at the article.