You know it's only a matter of time before some major studio pays millions of dollars to Michael Phelps for the rights to his phenomenal march into Olympic history with an unprecedented eight gold medals. So the question is, who would be best to play the long and lanky American hero? Do they cast someone who is tall with massive shoulders, or a normal-sized actor with a diminutive supporting cast to make him look large? Who do you think would make the biggest splash?