Most e-patients go online to read about a health condition. But that seems almost passive compared to the way a small group of Internet-savvy people are connecting to get their health information.

About 20 percent of e-patients go to Internet and social-networking sites where they can talk to medical experts and other patients, says Susannah Fox, with the Pew Internet and American Life Project.

"They are posting their first-person accounts of treatments and side effects from medications," says Fox. "They are recording and posting those podcasts. They're tagging content. They are part of the conversation. And that, I think, is an indicator of where we could be going in terms of the future of participatory medicine."