Mindy Pennybacker-Wallace, '74, has been helping consumers make smarter choices for the planet—and their wallets—for more than a decade. Formerly editor-in-chief of The Green Guide newsletter and website (now published by National Geographic) and current editor and publisher of GreenerPenny.com, her new book is Do One Green Thing: Saving the Earth through Simple, Everyday Choices (Thomas Dunne, 2010). She cuts through the "greenwashing" hype to provide straightforward suggestions of ways individuals can reduce their impact on the environment. Here are 10 modest changes that together save more than 6,000 pounds of carbon emissions a year—the per-person equivalent of three coast-to-coast roundtrip flights.