Agave nectar is from the agave plant--same plant that tequila is made from. (What could be bad?!) It is used as a sugar substitute, much like honey and can be found in both light and dark varieties. The benefit to using agave nectar is that it produces a low glycemic response and doesn't create the highs and lows that sugar causes. It can readily be found at health food stores (Whole Foods) or speciality stores (Trader Joe's).