The most convincing argument against it I have heard is the potential for producing defective individuals

but aren't we all defective? or is it just me?


EDIT: in response to your PS, Dr. Bill.. let's just cut to the chase. We all know that Dolly and her contemporaries were conceived without semen contribution(using a female's egg along a cell from another female). Therefore, if cloning were to catch on, there would be no genetic need for men. You are a man. You are therefore uncomfortable with this concept. Q.E.D.