The current deployment of large screens in city centre public spaces requires a substantial rethinking of our understanding of the relationship of media to urban space. Drawing on a case study of the Public Space Broadcasting project launched in the UK in 2003, this article argues that large screens have the potential to play a significant role in promoting public interaction. However, the realization of this potential requires a far-reaching investigation of the role of media in the construction of complex public spaces and diverse public cultures.