By Cindy Clark

Vote! That's the celebrity "it" endorsement of the year.

Non-partisan registration groups are enjoying a surge in celebrity participation this election cycle.

Some are helping target specific demographics: Wilmer Valderrama and Rosario Dawson made a public service announcement for the group Voto Latino. Others zero in on specific issues: Kanye West filmed a documentary about young veterans for MTV's Choose or Lose campaign.

Dave Matthews and Jack Johnson finance volunteers with the group HeadCount to tour with them and register voters at their concerts. And Sheryl Crow teamed up with Rock the Vote to spread the word by offering a free download of her latest album, Detours, to the first 50,000 people who register three friends to vote.

Others, including the cast of the High School Musical 3 movie and Ugly Betty's America Ferrera, are filming more conventional PSAs.

For High School Musical's Monique Coleman, 27, getting involved was a no-brainer. "It's a really important year," she says. "I'm not doing this for some sort of publicity stunt. … I'm in the position to have the ability to possibly make an influence."

Cast members from ABC Family's Greek are touring college campuses. Series star Spencer Grammer, 24, points out that it's much easier for a celebrity to advocate voting than to side with a specific candidate and risk alienating fans.

"Why wouldn't you want to get involved? I'm not saying 'Hey, go vote for this person,' I'm just saying 'Hey, go vote.' "

Marc Morgenstern, executive director of Declare Yourself, says: "We're contacted constantly by representatives or celebrities themselves. The celebrities really see this as an opportunity to model the right kind of behavior."

Star power is key, organizers say. "When we're trying to make politics relevant, the artists bring an ingredient that all of the funding and hard work can't replicate," says Andy Bernstein, executive director of HeadCount. "It brings a credibility and emotional connection to the issue."

This year, gains in registration among younger Americans are notable: 57% of those ages 18 to 29 say they are registered, a five-point increase over the past 12 years, according to the Pew Research Center for People & the Press.

Morgenstern says it's safe to expect more: "Young people are notorious procrastinators. A lot of people don't get around to (registering) until they're staring at those deadlines."