COLUMBIA - Thirteen virtual strangers were drawn this past Wednesday to a corner of the Barnes & Noble bookstore on Harbison Drive through the newest revolution in political campaigns: meetup.com.

The 13, ranging in age from their late 20s to early 60s, were supporters of Democratic presidential hopeful Howard Dean, who visits Columbia today. Along with more than 1,000 other Dean supporters statewide, they had been drawn out into the 39-degree weather by the power of the Internet.

Meetup.com is the 21st century version of the community bulletin board. It was founded in 2002 as a way for people with like interests to create and plan monthly meetings, and Dean's campaign discovered meetup.com could be used to harness grass-roots political energy.

Since then, meetup.com has became the latest example of how the Internet is changing campaigns.

Across the country, nearly 150,000 Dean supporters are registered at meetup.com. Retired Army Gen. Wesley Clark, another Democratic presidential hopeful, has more than 50,000.

Robin Burleson, 58, of Columbia, was at Barnes & Noble on Wednesday. She discovered meetup.com after volunteering for the former Vermont governor in October at the S.C. State Fair. Wednesday's gathering was her fourth meetup.

"It's all to get the word out about Dean," Burleson said. "We're that committed to what he's trying to do."

At the same moment Wednesday, Dean meetups were being held at Mac's on Main restaurant and at the Cool Beans coffeehouse on College Street.

Although Dean has the biggest numbers nationally and in South Carolina on meetup.com, he's not alone in using the connection.

Most of the major Democratic candidates have some presence on meetup.com. And the phenomenon's impact on South Carolina's Feb. 3 presidential primary could be significant, said College of Charleston communications professor Jamie McKown.

It's having a huge effect, at least in terms of mobilizing a group of voters who traditionally haven't gone to party meetings and not worked in the typical infrastructure, McKown said.

But meetup.com is not replacing traditional grass-roots politics, McKown said. It's replicating it.

Here's how it works: Supporters visit meetup.com and sign up for a group that they're interested in. It's not all politics. There are more than 850,000 people worldwide signed up for more than 2,600 different meetup topics, including fans of Buffy the Vampire Slayer, witches and stay-at-home moms.

Once a user signs up for a group, meetup.com sends out monthly e-mails reminding the group of their next scheduled event and the agenda.

Members of the group vote through the Web site for where the event will be held, generally choosing from a list of registered meetup locales. Meetup.com makes its money, in part, by getting businesses to pay to be meetup hosts.

Members of the group then RSVP for the event.

Burleson and the other members of this past week's Dean meetup, all of whom are volunteers, were busy planning for their candidate's visit to Columbia today. There's to be a rally at a downtown hotel and the grand opening of Dean's statewide campaign office.

Those gathered also discussed the need to get signatures from registered voters to get Dean's name on the S.C. primary ballot. Candidates either can pay a $2,500 fee or collect 3,000 signatures to qualify for the primary. Dean wants the signatures.

Two days earlier, on Monday, Hartsville High School teacher Bill Heitsman was among those at a meetup for Clark.

"I have been following all the campaigns and all the campaigns are on meetup if they're serious," said Heitsman, who teaches government and describes his age as between 57 and death.

"It's fascinating to me to see what the Internet is doing to campaigns," he said. "It reminds me more of the campaigns of the old days, when you had the union halls and the one-on-one, and not just the mass media you were treated to in the '70s and '80s."

Meetup certainly has made Susan Altrui's job easier.

As the Little Rock, Ark.,-based national volunteer coordinator for Clark, Altrui said the Internet tool has helped her find people to be volunteers and carry the torch for Clark.

In November, Clark supporters held 202 separate meetups. This past Monday, there were 311.

Clark and Dean are the most successful meetup practitioners for a reason, said McKown of the College of Charleston. They attract a certain kind of supporter.

Dean used the Internet to harness hundreds of thousands of dollars in donations. Clark supporters used the Internet for a campaign that, in large part, drafted the retired general to run for president.

It's not something that all candidates can do, McKown said.

Dick Gephardt's campaign is probably not as relevant to that base, McKown said, referring to the Missouri congressman who's counting on labor support, in large part, to fuel his bid for the Democratic nomination.

"You can't just assume that you can do like Howard Dean is doing, and not understand the dynamic of the Dean campaign, the Clark campaign, the non-traditional, disaffected voter."