Age: 53
First act: New Hampshire native founded organic yogurt maker Stonyfield Farms in 1983 and sold it outright to Groupe Danone in 2003. It's now the nation's No. 3 yogurt.
Second act: Hirshberg still holds the title of "CE-YO" of Stonyfield, but he has also launched O'Naturals, a chain of health-conscious cafés in New England serving up dishes like wild prairie-raised bison meatloaf. It's been slow going: After six years there are only five locations; two others have closed.
