1) Go outside. Take a walk, sit on your porch, have lunch in the park, eat a picnic dinner with family or friends. Looking outside doesn't count. Get out there and just...relax.
2) Plant something. If the idea of relaxing drives you a little bit crazy, do something useful. Plant a tree, sow vegetable seeds in your garden, transplant seedlings, fill your porch pots with flowers you'll enjoy the rest of the spring and summer.
3) Look out your window. Okay, for all you people who want to be "eco" but really hate the idea of digging dirt or lunching en pleine aire, pull up a chair to your favorite window and take a gander outside. Notice the birds in your yard, the buds on the trees, the clouds in the sky. Sound sappy? Maybe. Try it, just for half an hour. Let me know what it does for you.
4) Go see a movie. AFTER you've connected to your own backyard, connect to the world. "Nature," the new Disney movie, offers stunning cinematography of some of the most spectacular natural places on the globe. Plus, Disney is planting a tree for every ticket sold (so...it's an easy way for you to take credit for #2, above).
5) Swap stuff with your friends or family. So far, Earth Day is about the only major U.S. holiday that does NOT masquerade as an excuse for a shopping spree. Let's keep it that way. If you need something, send a note to your personal e-mail list and ask if you can borrow it or swap for it. You can also try Craig's List and FreeCycle.
6) Sign up for the One-in-a-Million Campaign. We've inspired thousands of people to shift their spending to products and services that offer the greatest environmental benefit. Joining the campaign is free, and over time, the actions you take will save you thousands of dollars.
7) Prepare organic food. If you've been thinking you should switch to organic produce, free range meat, and hormone-free milk, now's the time to make your move. You should be able to find organic milk, meat, and produce at your local grocery store, food coop, or natural foods store. If not, ask the store manager to order it for you. Give the manager your name and phone number and say you'd like to be notified when the items come in. Let the manager know you and your friends want to see more organics on the shelves.
8) Plug into a power strip. Computers, fax machines, printers, televisions, microwave ovens and other appliances use almost as much energy when they're plugged in but turned off as when they're turned on. Plug into energy-saving power strips (one in the office, one next to the family tv, one in the kitchen) so you can easily cut the current; the money you save will pay for the cost of the power strips.
9) Carpool, telecommute, bicycle or take mass transit. Burning gasoline for transportation is a major cause of air pollution, smog, and climate change. On Earth Day, change the way you commute to work or get kids to sports practice and music lessons.
10) Make every day Earth Day. Yes, it's corny, but it's true. Taking one action on Earth Day may make you feel good, but it won't add up to much unless it's repeated over time. Besides, don't you need an excuse to spend a half an hour just looking out the window?