Product directories:
Natural Foods Directory is a comprehensive, searchable directory of eco food, products, and services. Over 15,000 green businesses nationwide are neatly categorized and listed.
The EcoMall has a directory of environmental products, along with eco quotes, tips, and news.

Multi-product online catalogs:
Message!Products has checks that benefit the non-profit of your choice, such as World Wildlife Fund, National Organization for Women, and Amnesty International. Also has hemp products, tree-free paper and paper products.
Grass Roots has hemp and organically-grown cotton clothes (baby and kid clothes too), accessories, body care and other products. I order from them all the time -- prompt delivery and they're SOOO nice!

Office Products:
Recycled Office Products has office products (paper, hanging folders, recycled steel book racks, etc.) made from 100% recycled materials. Order online. I've ordered from them and they're prompt and reliable and have good customer service.
Green Line Paper Company has an online catalog of paper products including tree-free paper. To order call 800-641-1117.
The Real Earth has recycled, tree-free papers and stationery, and recycled content office products, gifts, and kids' stuff. They also have non-toxic and biodegradable cleaning products and recycled janitorial paper supplies. Call 800-987-3326.

Food:
The Country Hen's eggs come from hens that live in spacious, sunlit barns free from cages. The hens are fed certified (by OGBA) 100% organic feed. No salmonella has appeared on the farm in 7 years of testing. And the eggs taste great! (I know, because I eat them!)
Frontier Natural Products Co-op has botanical products -- organic coffee, herbs, spices, etc.
Thanksgiving Coffee Company supports growers' co-ops, organic and sustainable farms and traditional shade-grown coffee plantations. Their Song Bird Coffee protects the habitat of migrating song birds.
Earthbound Farm has 7,000 organic acres and 2,000 acres in transition. They make yummy salad mixes -- already washed and totally convenient.
Natural Selection Foods grew out of Earthbound Farm and helps organic farmers.

Travel:
Outer Edge Expeditions has environmentally-sensitive adventure tours all over the world (Borneo, New Zealand, South Africa, Peru, Turkey, etc.).
Earthwatch Institute offers expeditions where members help field scientists gather data in projects all over the world. Projects include: surveying hippo populations in Ghana, monitoring the endangered snow leopard in India, studying endangered sea turtles in Baja, Mexico, etc.
Green Tortoise Adventure Travel. See national parks, deserts, beaches, mountains, and forests all over North and Central America in Green Tortoise's sleeper buses.

Electric cars:
Solectria Corporation makes electric cars, vans, trucks and components.

Hygiene:
Tom's of Maine has great toothpaste, deodorant, and other fabulous and environmentally responsible bath products. I use their stuff and it's great! They also give 10% of pre-tax profits to non-profit organizations.

Cleaning products:
EarthSafe Products makes cleaning products using earth-friendly ingredients.

Clothing:
Patagonia makes high-quality fleece outdoor clothing from recycled plastic bottles and organically-grown cotton clothes. Their site also has environmental news.

Energy-efficient appliances:
ASKO washers and dryers use less water, detergent, bleach, and electricity than conventional washers and dryers. Phone 800-367-2444.

For kids:
HUGG-A-PLANET sells children's toys made from organically-grown, unbleached cotton. One of their products is an adorable, stuffed cotton bunny. Phone 914-833-0200.

Buying guides:
Union of Concerned Scientists' buying guide for green cars has info on electric, hybrid, and other eco cars.
The Co-Op America's WoodWise Consumer helps you reduce junk mail, find environmentally sound lumber, avoid clothing made from trees, and more. Call 800-58GREEN for a free copy.
Certified Forest Products Council has a listing of FSC-certified forest products.

Investing:
Pax World Fund is a mutual fund that purchases securities in pollution control, health care, food, housing, education, and leisure activities, and does NOT invest in weapons production, nuclear power, tobacco, alcohol, or gambling industries. Pax Fund has a 5 star rating from Mutual Funds Magazine, an A+ rating from U.S. News and World Report, and has the highest overall rating from Standard & Poor.
Calvert Group, the family of socially-responsible mutual funds. Has a white paper on the world's indigenous peoples.