Computer-based collaborative tools have been proven to be effective in supporting inhabitants of cities to participate more activeley in the decisions about the development of their cities and environment. These tools are also help them to organize themselfs and react more quickly to changes in the environment enabling at the same time the broad participation of its population in the decisions about its development. An example of this situation is triggered by a new law recently issued in Chile which aims to give its population an opportunity to participate in the decision about whether a new mobile communication antenna should be placed in their neighborhood and under which circumstances. This works proposes a new example of such a tool which allows citizens to gather and display the relevant information for such circumstances. © 2012 Springer-Verlag.