(The legend goes that he was working in his laboratory on a new ulcer drug when he mixed two amino acids, aspartic acid and phenylalanine. After accidentally spilling the liquid on his hand, he licked his finger and found it was sweet.
Today, a host of websites with names such as aspartamekills.com and sweetpoison.com warn that it is dangerous to health, and Pepsi recently announced it's dropping the sweetener from drinks in the US but not the UK.)