@jbshorty: Flamingo dosn't support NURBS, it render polygon meshes only. A good alternative is Vray for Rhino (www.asgvis.com) - an universal modern engine full integrated in Rhino (not for free). Vray can render NURBS, but VfR dosn't support it now.

The only NURBS render engines for Rhino ise Rhinoman+Renderman renderer. Rhinoman is a free plugin for several engines - AIR (not free) or 3Delight (free).

-Micha