The third MySpace/MTV presidential dialogue will feature another first when it hosts Arizona Senator John McCain on December 3 at a soon-to-be announced campus in the decisive early-primary state of New Hampshire.

After appearances by Democratic aspirants Barack Obama and John Edwards, McCain becomes the first Republican presidential nominee to take the stage for the groundbreaking format, in which candidates answer questions from college students as well as Internet viewers in real time and respond to instant feedback from users using the Flektor polling tool.

The dialogue will take place at 7 p.m. ET and will be the first to be simultaneously broadcast live on MTV, MySpace, ChooseOrLose.com and on mobile devices via MTV Mobile; and translated live into Spanish via ImpreMedia's LaVibra.. The forum will be hosted by MTV News correspondents Gideon Yago and John Norris, with online questions, polling results and commentary delivered again by moderator and WashingtonPost.com political reporter Chris Cillizza.

So far, the hour-long forums have allowed students and online users to quiz the candidates on a wide variety of issues, from funding for the arts to Iraq, stem-cell research, their religious beliefs and gay marriage. Clips of the previous forums in New Hampshire and Iowa can be seen on MySpace, ChooseorLose.com and on LaVibra.com.

McCain, a two-time presidential hopeful (he ran in 2000 as well), is a Vietnam War veteran who spent five years in a prison camp, and is unique among the leading candidates, Republican and Democratic, in his unwavering support for President Bush's Iraq war policies. He won the New Hampshire primary in 2000, but after a loss in South Carolina, his first White House bid lost momentum. McCain was considered a Republican front-runner early in the 2008 election cycle until his fortunes and fund-raising dipped substantially earlier this year amid defections from his staff and cost-cutting by his campaign, although he has rebounded recently in many key primary states. In New Hampshire, he is tied for second place with former New York Mayor Rudy Giuliani, behind front-runner Mitt Romney, according to a recently released poll conducted by CNN and New Hampshire ABC-TV affiliate WMUR.

The MySpace/MTV dialogues have provided the candidates with a relaxed, informal forum to voice their opinions and answer the concerns of students, many of whom will be voting for president for the first time in their lives. Since their debut, the video highlights from the two previous dialogues have been streamed approximately 700,000 times, and nearly 3.3 million people have watched them on MTV. More than 12,000 online questions were submitted for Senators Edwards and Obama during the first two events.