A new tech movement aimed at empowering citizens to remake their cities, called DIY City, launched in 2008 and involves forums where people can propose projects and then discuss the potential solutions.

Now, DIY Traffic, the initiative's first specific project, is underway in San Francisco, Chicago, and Portland. According to O'Reilly Radar, it uses Twitter to send and receive traffic updates from subscribers.

"Simple but potentially quite useful especially in a city that doesn't have traffic maps or if you travel on side streets," is how O'Reilly puts it. "DIY Traffic will accept traffic updates, let you send out an alert and let you query for the conditions on a specific street."

DIY City and DIY Traffic signal the convergence of three important trends. First is the democratization of city planning. Similar to the work the Personal Democracy Forum is doing to promote free elections around the world, this technology has the power to get everyone involved in decision-making and thereby harness collective intelligence to get work done quickly and efficiently. It's also a nod to the open-source media model promoted by Jay Rosen at NYU, who is little concerned with the future of investiagive journalism because everyone armed with an iPhone can now disclose anything they want, whenever they want, and advertise it to the world. Third is infinite potential of Twitter. And just when you thought they would never monotize. No wonder they turned down that offer from Facebook.