See the stars who want you to register and vote

Mark your calendars: The presidential election falls on Tuesday, November 6. But the only way to vote is if you're registered. In 2008, 6 million eligible voters could not fill out a ballot for president simply because they missed the registration deadline. No excuses: Celebrities and voting organizations have come together to encourage the electorate to register and vote.

Rock the Vote -- the nonpartisan voter registration organization, which has been reaching out to the youth vote through pop culture for 21 years -- has again launched a campaign, this time to encourage the Millennials to vote.

The video above enlists a wide cast of characters to encourage voting. Indeed, the full list is long: Miranda Cosgrove ("iCarly") to Vinny Guadagnino from "Jersey Shore". There's "So You Think You Can Dance" legend Twitch and "Community" star Joel McHale. Miley Cyrus. Chad Lowe. Mateo. Travis Wall. Ryan Guzman. Connor Paolo. Kathryn McCormick. Tony Hawk. Busy Phillips. Josh Duhamel. Kathy Griffin. Eric Stonestreet and Jesse Tyler Ferguson from "Modern Family". Neil Patrick Harris. And a team effort from the cast of "Glee": Darren Criss, Harry Shum, Jane Lynch, Jenna Ushkowitz, and Kevin McHale. And yes, there's a Twitter hashtag -- #WeWill.

Many of the stars have taken to Twitter to encourage their followers to vote. As Miley Cyrus posted, "#WeWill be heard! I'm in @Rockthevote's new PSA. Watch, register, and make your choice this November!" Translation: If Miley can do it, so can we all.

Rock the Vote isn't the only organization working on voter registration. Some A-listers are making an appeal with Our Time videos, such as one from comic actor Steve Carell -- who threatens in a short clip to come to your house and "box your ears" if you don't register.

And avoid an ear-boxing from Steve Carell.

With the Millennials making up one-fifth of the electorate in 2012, the race is on to register as many young voters as possible.

But it's not just young folks who need to pay attention to their voting status. A whopping 51 million eligible voters are currently not registered. This could mean you.

In order to reverse the trend, a massive outreach is happening on Tuesday for National Voter Registration Day.

The deadline to register varies by state -- but all the dates fall in October. Register to vote by going here now.