Even though he's a novice at organizing political events, John Huffman wanted to stoke interest among his fellow twentysomethings in advance of the Democratic presidential primary.

A guitarist with the group Delorean Showcase, he went to a Web site that combines social networking with campaign events and posted an announcement for a Rock For Obama event on a recent Saturday night at the Bloomfield Bridge Tavern.

"I don't think a lot of people my age vote," said Mr. Huffman, 26, of Lawrenceville. "So we're trying to get the message out. I'm just doing what I can to make a difference."

Just about everyone who showed up for the evening of modern rock, pierogies and french fries looked so young they were carded. A beer pitcher was placed on a table near the entrance to collect loose dollar bills as campaign donations. Campaign material was handed out, with one young woman placing her Obama sticker on the back of a jeans skirt worn over pink fishnet stockings.

What impact such events will have on Tuesday's voting remains to be seen, but several dynamics are in play. On the whole, young people do not vote as regularly as other age groups, but this year that number may change. And a generation raised on YouTube, MySpace and Facebook has found a new and different way of discussing politics.

"More young people are involved in this election than they have been in the last 20 to 30 years," said Scott Keeter, director of survey research for the nonpartisan Pew Research Center, in Washington, D.C. "Nationally, 14 percent of the electorate is made up of those aged 18 to 29, a jump from 9 percent in 2004. For all this noise, they remain underperforming in terms of turnout percentage compared to what we see in other age groups. But there is definitely an uptick."

They also tend to use their laptops and cell phones to receive and share information, and the impact of these communication tools is still evolving. In 2003, former Democratic presidential candidate Howard Dean became a pioneer by using the Internet to allow supporters to self-organize.

While grass roots is a familiar term in politics, net roots is just emerging.

All of the candidates have Web sites and court the younger set, variously described as Generation Next, Generation Y, Dotnets or Millennials. For example, Chelsea Clinton has visited 100 college campuses on behalf of her mother, and Meghan McCain has a YouTube blog (Mccainblogette.com) about her father's campaign.

But Mr. Obama's supporters use their computer networks more often to coordinate and communicate within their ranks. Even before he formally launched his campaign, the Obama campaign produced an online video in early 2007 that described mybarackobama.com "as a tool to organize your friends, your neighbors and your networks."

According to the online monitoring service Compete, the Obama site gets twice the traffic of his Democratic rival. And neutral political observers say the Obama campaign is pushing the edge of the envelope in rallying a high-tech army of volunteers.

One example is obamaworks.com, a concept described by Yale University students Justin Kasslyn and David Manners-Weber as a way to combine community service projects with a campaign that called for change in the way things are done.

"In a lot of ways, it's invisible," said Mr. Skeeter. "But 62 percent of young people use social networking, and one in four gets campaign information from a social network. Those are eye-popping numbers. I think the Obama campaign has been much smarter than any of the others in harnessing the energy of self-organization. Young people are a very critical voting bloc for him. It's kind of like the wild card in this election."

Blogger John Morgan (thepennsylvaniaprogressive.com) has quantified national interest in the Pennsylvania primary by the number of hits on his site.

"On a bad day, it's four or five times what it was before this election," he said. "There are dynamics at play that I've never seen before."

While Hillary Clinton may have the endorsements of the governor, big city mayors and politicos from around the state, the Obama campaign has a better grasp of augmenting traditional politicking with new communications tools, said Mr. Morgan, 56.

"Hillary's operation is top down. Obama's is grass roots from the ground up. Hillary's Web site is a lot harder to use and has nowhere near the online outreach for event planning," he said.

In Pennsylvania, the networking was tweaked by Adam LeGrand, 25, of Philadelphia, who enhanced the campaign's reach by creating an e-mail template capable of reaching volunteers in other cities and other states.

"I am a self-described giant nerd," laughed Mr. LeGrand, an architect who matches his time online with his 40-hour-a-week job.

He says the networking, which was the subject of an MTV.com report, taps into a feeling among the younger set that community service should be the foundation of national politics.

"It seemed like a great outlet for a lot of pent-up energy. Young people are being energized in ways they never have before," said Mr. LeGrand, who has never been involved in politics before.

The Pittsburgh chairperson of Obama Works is Sue Figel, who is also team captain of Obama volunteers in Monroeville. Wired to the extent that she gets e-mail on her cell phone, she has used the web site to organize a clean-up on the South Side. Sixteen people signed up electronically, but only four people showed up on a recent Saturday. It doesn't dim her hopes for her candidate.

"This is how it works. It always starts out small," she said. "He's what we've been looking for."

On Wednesday night, when the televised debate was up against the Penguins playoff game, just about every bar on the South Side was tuned into the hockey game. But Ashley Hodges, 22, helped organize a watch party on the second floor of the Library Cafe that drew about 50 people, many of them young professionals.

As the leader of the South Side For Obama, she has switched her registration from Independent and is doing volunteer work for a campaign for the first time. That means going door-to-door or making phone calls on behalf of the campaign, or showing up at events like Rock For Obama.

"I believe that change doesn't happen unless we're willing to make sacrifices," she said.