Sustainability is more than just the cause du jour for Ellie Daniels and her crew at the Green Store on Main Street in Belfast. They were selling nontoxic baby toys before nontoxic was even a word. Founded fifteen years ago by Daniels and three friends — who have since left the business — with thirty thousand dollars and absolutely no experience in retail sales, the store has become a mecca for people who want to live lightly on the planet. It’s still in the same ancient building with tin ceilings and a funky wooden floor, and it still sells the constantly popular plastic bag dryer, a wooden contraption with eight fingers that lets you wash and reuse those plastic bread bags until they can’t be used again — at which point Daniels will tell you to cut them into strips to tie up tomato plants. 71 Main St., Belfast, 207-338-4045, www.greenstore.com