Earth Day was founded to educate people about the environment and to focus on nurturing and renewing the Earth. Many people chose to celebrate an Earth week or an Earth month as well. The day was declared because if each person spends at least one day a year raising awareness about the environment, a difference can be made. Here are 10 ideas about how to get involved.

Remind yourself what's at stake: Visit nature. The Nature Conservancy has a handy interactive map of all protected lands in the United States. Perfect for a last-minute refresher course. (More at Nature Conservancy)

Learn about the history and evolution of Earth Day: Not so long ago, most Americans had little knowledge about the myriad ways we were poisoning our environment. A typical success story: In 1996, the bald eagle was removed from the endangered species list, reflecting its recovery since the 1972 DDT ban. (More at EPA)

Use less energy: Look for appliances rated by the federal government's EnergyStar program, which can help you save as much as 30 percent in energy costs while also reducing your emission of greenhouse gasses. (More at EarthDay.gov)

Learn what's in what you put on your body: The Environmental Working Group has published a searchable database on more than 14,000 products -- everything from lotion to lip balm -- and the 7,093 ingredients that form them. (More at EWG)

Recycle your stuff: Or give someone else's stuff new life. Local Freecycle groups work together to match clean, workable and still-usable items with people who need them. (More at Freecycle)

Turn off the tap: Did you know know that you may waste as much as 8 gallons by leaving the faucet running while brushing your teeth? Or that a leaky toilet wastes as much as 200 gallons a day? (More at Water Sense)

Leave the car home one day a week: By driving to work with a colleague, using mass transit, walking or bicycling, a commuter can save about 1,200 miles on their vehicle, about $455 in total driving costs. (More at It All Adds Up)

Calculate your carbon footprint: To misquote The Police, every breath you take and every move you make creates carbon dioxide, trapping heat in the atmosphere. Even the computer you are reading this on makes an impact. The more carbon dioxide you emit, the bigger your carbon footprint. Calculate your footprint and learn how to make simple changes that will shrink it. (More at Carbon Counter)

Eat green: The Center for Science in the Public Interest has an online calculator where you can measure the impact of the foods you eat on the environment around you. (More at CSPI)