If you have a cat who spends time outdoors, consider bringing him inside instead. Cats kill about 3.7 billion birds and nearly 20 billion small mammals -- like rabbits and voles -- in the United States every year. Outdoor cats also live shorter lives. To transition your cat from an outdoor dweller to an indoor one, install several scratching posts and open cardboard boxes throughout the house. This will make indoor living less dull and slowly acclimate him to his new lifestyle.

Restaurants and commercial kitchens throw away tons of food every year -- it's considered excess inventory, even though it could be given to food banks or hunger charities. One of the problems of getting the excess food to the charities is that often there isn't enough manpower to take the food to the shelter. Contact your local food bank or hunger charity and ask if it needs any volunteer "food runners." You literally donate time to pick up excess food (that's been properly packaged by the commercial kitchen) and bring it to the charity. It's one easy step to stop waste and alleviate hunger.

If you're having a party for a large group of people and you rent glassware, dishes and flatware from a rental company, it may seem rude to send them back dirty, but it isn't. The reality is, even if you do a thorough job in washing your rentals, the companies are required to use a commercial-grade dishwasher to fully clean and sanitize them before they go out to another party, so they are prepared to clean them anyway. Also, if you've got a sink full of dishes from a party, use the dishwasher: A loaded automatic dishwasher is much more water- and energy-efficient than washing by hand.