The infamous "Terminator Shadow" problem

Hi ! I'm wondering if that would be possible to get rid of (or atleast reduce) the terminator problem.

This effect appears in most ray-traced engines but some have found the solution like Mantra (Houdini) or VRay.

This problem happens when using smooth shading on a low poly mesh. I guess the rays from the rendering engine hit some of the faces but not others which results in those ugly shadows.

Now I know this is not a bug since that's the way ray-traced engines are supposed to work but a lot of blender users don't have super-powerful computers (or render farms) so we have to decrease the poly-count and use tricks like normal maps, bump maps,... to get the details back in but then the problem kicks in.

For a single image render, it is possible to bump the subdivisions up and hide the effect but for a complete animated short it is just impossible.

Here's an example of the problem (left : 4 subdivisions levels - right : no subdivisions) It is especially visible on the chin.