The Fortune Most Powerful Women isn’t only about Fortune 500 bosses and world-renowned business builders like Oprah Winfrey.

Today we unveil a new program and annual list called Most Powerful Women Entrepreneurs. It’s the right time to broaden the power base of the MPWomen community and honor outstanding builders of start-ups across the U.S. Small business, besides employing more than half of the U.S. workforce, is the main engine of the economic recovery.

To seek MPWomen Entrepreneur nominees, Fortune and our partner in this new venture, American Express –specifically, its OPEN card division, which serves small business–reached out to various sources, including the Small Business Administration and participants of the annual Fortune Most Powerful Women Summit. Wellpoint CEO Angela Braly, Gilt Groupe CEO Susan Lyne, and eBay Marketplaces President Lorrie Norrington are among the leaders who suggested candidates. From a field of 65, we elected 10 to honor this year.

All 10 winners participated in the MPWomen Summit this past September and were feted at a reception where the guests included Warren Buffett. He’s one of the few guys who comes to the Summit, and his company, Berkshire Hathaway , happens to employ some outstanding female CEOs. Buffett introduced a MPWomen Entrepreneurs panel that featured several of the 2009 winners, along with SBA Administrator Karen Mills.

FEED Projects co-founders Lauren Bush (left) and Ellen Gustafson. Photo courtesy of FEED Projects.

Over the next two weeks here on Postcards, we’ll tell you about four of this year’s MPWomen Entrepreneurs. Today, we’re introducing you to Lauren Bush and Ellen Gustafson, the co-founders of FEED Projects. They raise money and awareness for the UN World Food Programme by selling eco-friendly burlap tote bags and backpacks. FEED’s partners include Whole Foods , Barnes & Noble , Amazon , Kenneth Cole , and Bobbi Brown, the cosmetic marketer that is part of Estee Lauder .

Fortune and American Express chose FEED because we’re impressed with their social relevance: Since they started in 2007, FEED has raised over $5 million to buy more than 50 million school meals for children in the developing world. We’re also struck by FEED’s innovative branding. A big FEED stamp and a numeral mark every FEED bag, signifying the type of donation that the consumer has made by purchasing the bag.

Bush and Gustafson serve meals to children in Kenya with the UN World Food Programme. Photo courtesy of FEED Projects.

Bush, who is the niece of President George W., and Gustafson are 25 and 29 years old, respectively–so FEED, of course, is active on Facebook and Twitter. But the MPWomen Entrepreneurs’ ingenuity in communicating with consumers serves as a model for any marketer eager to go beyond the norm in social networking.

Here’s Lauren Bush on how FEED got started and what she’s learned about building a business:

Click here to see me talking about the Most Powerful Women Entrepreneurs initiative and to find out which other companies we’re honoring this year.