—Pervasive computing technologies can enable very flexible situated collaboration patterns among citizens and, via crowdsourcing, can promote a participatory way of contributing to the wealth and quality of life of our urban environments. This position paper firstly sketches a future vision of pervasive computing rich and crowdsourcing-enabled urban environments. Then, it presents several case studies showing how such environments can be of great use and highly impactful from both the individual and societal viewpoint. Finally, it discusses several open research challenges to be faced for these ideas to become reality. Keywords- Crowsourcing, Urban Computing, Human Computation.