This is a cool little project:

Real Time Copenhagen is a 3 year research project by the MIT SENSEable City Lab’s in collaboration with the Municipality of Copenhagen. Within this framework, CopenCycle is a short-term project in the context of a workshop which explores the use of real time technologies to map the flow of people and resources in Copenhagen to better understand urban dynamics in real time. By revealing the pulse of the city, the project aims to show how technology can help individuals and the planning institutions to make more informed decisions about their environment with a special emphasis on the use of public spaces. In the long run, the project seeks to integrate the technologies for more detailed studies of e.g. bicycle movements, services and routes in relation to sustainable urban transportation.

There are a bunch of cool components, including an "I crossed your path" ap for Facebook and a set of interfaces that help users track "personal bicycle habits including average calories, time, km’s, exercise, recreational riding, cost on a daily, weekly or monthly basis," compare the footprint impacts of their biking to other modes of transportation and so on.

Smarter cities can be dramatically more sustainable cities, and we are gaining the capacity to weave intelligence through our cities with increasing rapidity