After spending much of the presidential campaign season using his star wattage to get other people to the polls, Diddy, like other celebrity political boosters, spent the day leading by example. He arrived at his polling site - a school in midtown Manhattan - in the morning and waited in line as a bevy of media prepared to capture the moment.
Diddy said he believed he was potentially making history by voting for the first black president in U.S. history, and also felt the weight of the past in the voting booth.
"I'm not trying to be dramatic, but I just felt like, Martin Luther King, and I felt the whole civil rights movement, I felt all that energy, and I felt my kids," he said. "It was all there at one time. It was a joyous moment."
Pete Wentz, bass player for Fall Out Boy, showed up at his polling center in Beverly Hills, Calif., which turned out to be the garage of a private home. The longtime Obama and Joe Biden supporter who also rallied against a California proposition that would ban gay marriage, said his vote "feels important."
"I don't usually go out of my way to indoctrinate people or tell people, 'You should do this because of me, or you shouldn't do this because of me,' but I think it's important for people to get out there," said the 29-year-old rocker. His pregnant wife, singer Ashlee Simpson, wasn't with him, but Wentz said she would be out later to vote.
For Wentz, the vote for Biden for vice president was more than important - it was personal.
"I would not be standing here actually in reality at all because my parents met working for Biden," he said. "They met on the campaign, so they have this particular affection for Joe. He came to their wedding. If it weren't for Joe Biden, I would not exist as a human being."
Singer and actress Brandy was in Manhattan on Monday to promote her upcoming album, but planned to fly back to Los Angeles to cast her vote for Obama.
"Our world is changing. It's changing right now, and I'm so happy to contribute to that," she said. "I am excited, and I'm going to take a picture of it."
Country star Taylor Swift, who declined to say whether she was voting for Obama or John McCain, waited in a long line a few days ago to vote with her mother in Tennessee - and was so happy, she recorded the event for one of her video blogs.
"I was really excited because I got to vote," the multiplatinum singer said in a weekend interview. "I early voted, and I was really excited to be able to do that, and it was really something that I was looking forward to all year, ever since I turned 18, so that was really fun."
Usher, who was one of Obama's most active celebrity supporters, said young people like Swift were energized by this year's election, and he credited Obama for connecting with that particular voting bloc.
"This campaign has definitely engaged youth on a level like none other. Like never ever before," the 29-year-old entertainer said Monday night. "Now something has truly happened to make a difference. We now recognize that we have a voice. We now recognize that through service we can make a difference. And you can speak up."