The buzz around genetically modified organisms (GMOs) has grown to a fever pitch in recent months, with approval by the U.S. Department of Agriculture of three new kinds of genetically engineered (GE) foods: alfalfa (which becomes hay), a type of corn grown to produce ethanol, and sugar beets. And the approval by the Food and Drug Administration of a super-fast-growing salmon — the first genetically modified animal to be sold in the U.S., but probably not the last — may not be far behind.