If you've ever given a prepaid credit card gift card -- the cards with the Visa, MasterCard or American Express logo on them -- you might be surprised to know that more than $5 billion dollars on these cards never get used. If you have a stash of gift cards with a small balance on them -- even just a penny -- you can donate the leftover balance to help make the world a better place. Many nonprofits like the Salvation Army and the American Society for the Prevention of Cruelty to Animals have made it easy to give; just visit their websites and enter the details of the card and whatever balance you want to give is donated. Can you imagine if we all did this? Amazing things could happen.

Can you recycle your old undergarments, like underwear and bras? Yes, you can. Believe it or not, Goodwill takes any condition undergarments, as long as they are clean. If they are in good enough shape, they'll sell them in their stores. If they are torn or threadbare, they get sold to scrap fabric dealers who recycle them into new cloth industrial products. But here's something you may not know: If you wear 100 percent cotton undergarments, you can compost them. Just cut off the elastic parts and cut the cotton fabric into small pieces. Toss the scraps into the compost, and in no time flat, they'll break down into beneficial mulch for your garden.

Is it greener to shop online or at the store? The answer depends how far you drive. If you live near stores that are in close proximity of your house -- less than 10 miles away -- buying locally is the greener way to go. But if you drive more than 20 miles round trip to a store, buying items online will be more environmentally friendly and probably more convenient to you. Even with overnight air shipping, The Center for Energy and Climate Solutions says two 20-pound boxes is more energy efficient to order online and have delivered than driving those 20 miles. The trick to be the greenest is to elect ground shipping and to buy only what you need.