Is a different (from the global Internet and Cellular Networks) model for urban communications and networking conceivable? Can Community Networks, now flourishing in many parts of Europe and the world, be the next 'big thing' in networking, for once considering the needs of people and urban evolution as a key element, and not as a side effect of technology or business? This paper discusses recent evolutions of Community Networks in Urban Areas, blending the technical analysis of their topology and evolution, together with grand challenges ahead and the need for a novel, transdisciplinary science that can guide the design of the future communication space for smart cities and beyond.