One of its latest ventures: its own social network, built on Ning -- a roll-your-own social network platform launched by former Netscape founder Marc Andreessen and Gina Bianchini in October 2005.

The ASPCA already boasts a comprehensive Web site, a MySpace page , a Facebook fan page and Facebook Cause page, a space on the Bebo social network, and a YouTube channel . "We always keep looking to see what is new and can help us engage our audience and where is the greatest benefit," says Shonali Burke, the vice president of media and communications for the ASPCA. "There's potential for growth in the online sphere, and we're always experimenting."

To that end, last June the ASPCA hired Elyse Orecchio for its newly-created position of associate editor for social media. Orecchio says the ASPCA Online Community on Ning was launched in October 2007, and it already boasts more than 8,000 members. She attributes the network's popularity to live chats with experts, who answer members questions about topics like animal-assisted therapy, humane education, and animal poison control, and also dispense free veterinary advice.

One advantage of the ASPCA Ning network, says Burke, is that it "encourages conversation and enables people to connect in ways that are less limited than on the other social networks." For example, members of the organization's Ning network have formed groups like "Dogsville" and "Catsville," where participants swap thoughts, information, tips, and ideas. The number of potential groups is unlimited, and members can upload photos and videos and easily make connections because every member, by self-definition, has much in common.

Nonprofits can form their own social networks -- at no cost, except for the time investment required -- not only on Ning, but also on Grou.ps , CrowdVine, and Agork . Ning, host to more than 220,000 networks, is both prominent and well-funded.

While the ASPCA is larger than most nonprofits and therefore can devote more resources to online communities, like every other organization it still faces limitations. "One of the constant questions about social media," says Burke, "is 'How many can I do?' Our Ning social network is helpful because it's all contained in one space." Orecchio says the ability to control the network and keep track of traffic and user sessions are the types of capabilities that are very valuable -- and not available on MySpace on Facebook.

The creation of your own social network can be down gradually, and one other advantage is that it can grow organically -- as new members of the network make their own contributions. While Burke believes that the ASPCA's Ning network is a great asset, she says that the ASPCA continues to look to where it can reach current and potential members -- Twitter is becoming more intriguing, she says -- you still have to look at the big picture.

"The challenge for any organization is how to you start connecting the dots? You have traditional media and online media -- how do you get those pockets to intersect, and how do you increase engagement?"

With the continuing growth of the Web and other communications options, there may never be a single place where an organization's community congregates, either online or offline. But by creating your own social network, you may be able to get one step closer to providing employees, volunteers, and members a place to call home -- a place, to paraphrase Dr. Doolittle, where when you get there, you know you've arrived.