Hi Michael. A similar thing can be done in Rhino by using the SurfaceCreasing plugin, which allows you to output a creased single surface from commands such as Extrude, Sweep, Loft, etc. Any kinks in the curve will become a crease. Of course, it has the same toplological restraints as a single surface. But it can be point edited... It can be a very useful tool, but dangerous in the wrong hands! Many times resulting in the question "why can't i fillet this edge?". And the usual response "because there is no edge there!" :P

jonah