I recently finished up school, and part of that was finishing up my ray tracing project. At the last minute, I implemented Gouraud shading which is a technique to try to smooth out a triangulated surface. What it really does is just linearly interpolate the normal vectors, where the normal of a vertex is calculated as a weighted average of the normals of the triangles using that vertex.
Long story short:
A render of the Stanford bunny with my raytracer without Gouraud shading.
A render of the Stanford bunny with smooth Gouraud shading.
Also, thanks to an improvement in my parallelization of the problem and a speedup in octtree traversal, I was able to render the Stanford dragon model (~1 million triangles):
The Stanford dragon model.