From the site:
"Obscura Digital created a physical, social, augmented reality experience dubbed "Connections" at F8, Facebook's developer's conference. Attendees swipe in to the experience using their RFID enabled event badge. Multiple overhead projectors map visuals to the floor and an array of 3D cameras are used to reliably track any number of people within the space.
Once “logged in” to Connections, a radial visualization, constructed from the user’s social graph data, surrounds them creating a unique “fingerprint”. Colored lines extend from the circles connecting people who share one or more of the observed metrics (mutual friends, interests, workplaces, schools, locations, birth sign, or non-English languages). When two or more people, who have mutual connections, stand within close proximity, a slideshow of mutual friends and interests appear between them.
Positioned behind the Connections space, a large screen shares aggregate data about the collective group- surfacing common interests and profiling the most connected of the group."