Once the domain of college students, Facebook has more than 200 million active users worldwide, and the fastest growing group of users is those ages 35 years and older. Traffic on Twitter, the astonishingly popular messaging service, doubled in March alone. Now millions of people "tweet," posting updates limited to 140 characters, similar to a text message on a cell phone.

Even skeptics would have to concede that social networking on the Internet is more than just a fad. And it was only a matter of time until specialized sites for nurses-such as http://Allnurses.com or http://NurseConnect.com-provided virtual watercoolers for swapping stories, gripes, and tips. But is the phenomenon of value to nurses? Some think so.

Online social networks can break down barriers that keep nurses apart. "Nursing can be very specialized," said Michael Lord, a critical care nurse in Philadelphia. "And our individual unit cultures can be quite different from the cultures of any of the specialties." He frequents http://Allnurses.com, http://Nurse-anesthesia.org, and sometimes nursing groups on Facebook. Lord enjoys bouncing ideas off nurses around the country, sometimes comparing his hospital's protocols with theirs. Beyond the exchange of facts, he said, online networking allows him to encourage and support newer, less experienced nurses and to find mentors of his own.

Wendy Jones, who works as a surgical ICU nurse in Texarkana, Texas, doesn't use the specialized networks much. She's a fiend on Twitter, though, where she goes by "@nursewendy" and has more than 3,600 followers. Twitter, she said, attracts "smart people who actually have something to say," as compared with Facebook and MySpace.

She's become friends with some physicians on Twitter, including a neurosurgeon, something that can be hard to do in person. "It's easier to feel on a par with them on Twitter than when you're in the hospital and they're giving orders," she said.

Scott Hensley