One 10"X10" foil piece of origami paperDesign:
Robert J. LangBook: Origami Design Secrets I
I think this would be High Intermediate
This model took me about an hour to fold.
You can view Robert J. Lang's website here
The paper was invented in China, but the art of origami is Japanese ("origami" means "paper folding" in the Japanese language).EDIT
: Thank you to everyone who has viewed and/or added this photograph to their favorites! I wish I could thank all of you individually (which I have attempted to do and has now become nearly impossible).
Thank you to ~Orestigami for fixing my summary.