>I gotta back up Marty a bit here. While I don't necessarily completely agree with his solution, it does adequately reflect that to support polymorphism, you have to have some branch logic somewhere

Right, but I prefer the compiler/runtime take care of it. This simulates each object simply "knowing" what to do, when issued a polymorphic command. At the practical level (which is what really counts), those kind of switches are a maintenance burden that is best avoided.