"I just don't think Harry's scar is the horcrux. I think the entire person or creature would have to be the horcrux, not just some physical feature of that person."
That said, what about Professor Quirrell being used
by the parasitic Voldemort? Both were able to function
independently despite V's having ensconced himself
inside Quirrel. When Quirrel died, V left to find
another host.
Good point, but I don't think Quirrell is the horcrux. He was being used, like Ginny was as well, but that doesn't make him the horcrux. I just can't buy the whole idea of Harry's scar as the horcrux. Plus, every time I read about "Harry is the horcrux" I think of "Horton Hears a Who" or whatever that Dr. Seuss book is called.