Now that basically everyone and their mother has seen W+K’s “Write the Future” spot for Nike (almost 17 million YouTube views and counting), the agency is taking things up a notch by letting the audience “Write Your Headline, Write the Future” with an interactive extension of the campaign that’s set in the heart of Johannesburg.

The fourth largest building in ground zero of the World Cup, the 30-story Life Center, is being converted into a digital billboard of sorts between 6pm and 6am that not only displays 90-meter-tall images of Cristiano Ronaldo and Robinho, but select personal messages (57 characters or less) sent by fans via Twitter (#NikeFuture), Facebook, QQ (in China) and Mxit (in South Africa) to any of 50 Nike-endorsed soccer pros.

In addition, W+K also launched a Facebook tie-in on Nikefootball.com where those who like to live vicariously can do so via a personalized “Write the Future” film that’s generated with the help of of your FB photo and profile.

More: “Nike ‘Write the Future’ Sets Viral Record”