Editor's note: Social media has quickly grown from a fun pastime to a serious business tool. And it's not just major corporations or CEOs who are blogging, Facebooking, and YouTubing. Portfolio.com and bizjournals take a look at how nonprofits increasingly turn to this medium as a way to reach audiences they didn't have access to before. Today, we begin with a look at how smaller organizations are getting wide exposure. Wednesday, we'll see how social media is leading more people to take action for good causes. And Friday, we'll learn about how social networking is encouraging novel forms of grassroots charitable giving and activism.

When Lynda Mitchell learned that her son Matt had life-threatening food allergies nine years ago, she got online and sought out other parents of children with the same problems.

Through those contacts she created an email list that formed the basis of what is now a national nonprofit, Kids With Food Allergies. The organization has a website with more than 17,000 registered members, as well as a presence on Facebook, MySpace, and Twitter.

“At any time of day, we have 300 messages posted [on the website],” Mitchell said. The messages are from “parents looking for anything from social and emotional support to how to make a birthday cake for their child tomorrow.”

Kids With Food Allergies was ahead of its time in realizing the social power of the Internet. Today, it has a lot of company.

Eighty-eight percent of the nonprofits that responded to a social-media survey by Sage North America, a business software firm based in Austin, Texas, said they are using some form of social media.

Social networking sites such as Facebook and MySpace are the most popular social media among the respondents, which consisted of 17 percent of the roughly 39,000 subscribers to the Chronicle of Philanthropy. Blogging and microblogging, which covers Twitter, followed in popularity. The survey also found that YouTube is widely used.

The newness of social media was reflected in two survey findings: that more than half of the nonprofits that use social media have been doing so for less than a year, and only 9 percent are very satisfied with them.

Sage Communications, a public relations firm that works with nonprofits, is advising its clients to wade into the social-media water slowly and to make sure that whatever they do connects to their overall strategy for presenting themselves to the public.