Would it be possible to tell who the most genetically diverse human is? What significance for adaptation would there be with a person of such genome? Would that person likely have been born in the United States?
Do you mean which human population is the most genetically diverse? Because as Andy said, an individual can't be diverse...well, unless he also contained DNA of a dead twin or something.
In general, human populations in Africa have a greater genetic diversity than in other parts of the world, which makes sense based on the Recent African Origin theory of the origin of modern humans.