Combine Bike Racks and Bike locks to allow for people to exchange their locked up bike for a key to unlock their bike.
Every one real spent by the brazilian government on the World Cup and alikes should be compensated by one spent on public schools.
People would walk more than they drive if there were moving walkways above the streets, all along its whole path. #rollingstreets
Virtual public email. Service. Redirect. Embeddable. Button. Instant. Anonymous. Preformatted for easy filtering. Can be @you or @you#topic
People should use live fence insted of ink. Not only good for the enviroment, but also avoids graphity vandalism. Green city insted of grey.
Car horns that gives an electric shock if pressed for more than 3 seconds in the city traffic.
Create an Artificially intelligent teaching application that tutors students remotely using open source technologies...