The European Union has created the European Institute of Technology (EIT), within which ICT Labs focuses on fostering exchange and new result creation in the sphere of Information and Communication Technology, across the areas of research, higher education, and industrial innovation. ''Digital Cities of the Future'' is an action line (or chapter) of EIT ICT Labs. Within this action line, we coordinated an activity called ''DataBridges: Data Integration for Digital cities'', whose aim is to produce, link, integrate and exploit open data in the Digital Cities data space, for the benefit of both citizens and administrations. In that context, DataBridges addresses many research challenges such as acquiring (or producing) Open City Data in RDF, data linking and integration, data provenance, and visualization. This position paper describes our efforts within DataBridges to integrate City Data. We provide a brief introduction to EIT ICT Labs, its goals and structures, and how DataBridges fits them. We then detail the activity and some selected results from 2011 - 2012, and plans for 2013. We conclude with some research challenges we plan to adress in the future.