OK, so what's this all about. From the site:
We all know the "Six Degrees of Separation" theory: Everyone knows everyone within six degrees. Keeping this in mind -- if you agree to vote, and you get all your friends to agree to vote, and they get all their friends, and so on, then, theoretically, everyone will be voting November 2nd. Even Kevin Bacon. Six Degrees of Voting.com serves to facilitate that concept. If you signup, you are pledging to vote on November 2nd. Get excited, this is an important election. You will then get a link that you can send to your friends and family.
So, as I've said, I'm registered and I'm voting. See how many of your friends/family are.