Nodes have been set up in Bath, University College London, the University of California in San Diego, with more nodes going online in Sweden, Hong Kong and Sydney.
He added: "When you return to Facebook you will see a list of all the devices you were near and the link to profiles of people who have tagged themselves on Cityware."
The Facebook tool is part of a wider project looking at issues around pervasive computing - connected devices in the environment.
"We are interested in understanding how cities work, how people move around. More recently we have been looking at how viruses spread in cities - biological and digital viruses."