Abstract. Public spaces are interactive by the very fact that they are designed to be looked at, walked around, and used by multitudes of people on a daily basis. Architects design such spaces to create physical scenarios for people to interact with, but this interaction will usually be one sided-the physical space does not usually change or react. In this paper we present three interaction design projects which add reactive dynamics into objects located in public spaces and in the process enhance the forms of interaction possible with them.