At a recent IT symposium at the Massachusetts Institute of Technology, one area of study discussed was digitally augmented urban environments.

Carlo Ratti, director of the school's SENSEable City Laboratory, says the lab is examining "the interface between people and mobile technology and cities. Wireless changes the way people live and work."

Researchers in the group have been using MIT's urban area in Cambridge., Mass., as a living lab. The campus achieved 100 percent Wi-Fi coverage in late 2005 and now has 3,000 access points. The staff monitors 104 buildings.

Once the infrastructure was in place Ratti's group started to log and analyse traffic patterns, generating heat maps and graphics of usage statistics that provided a real-time picture of what the MIT population was up to at any given moment.

Researchers followed up with the release of iFind, downloadable PC client code that, through triangulation, provides information about a user's location. Users decide when they want to be visible and to whom, and then can find friends and colleagues at a glance. About 1,500 of the 20,000 people on campus have downloaded iFind.

These humble first steps led to grander experiments overseas. The lab, for example, teamed with Google and Telecom Italia in Rome to see how much real-time information they could collect about city activity by monitoring cell-phone traffic patterns and taxi and bus movements.

Information superimposed on aerial photos showed cell activity as a red fog -- the deeper the colour, the more intense the traffic -- while buses and taxis were yellow trails. The cell traffic showed the city waking up; at rush hour the main thoroughfares showed high-density cell traffic -- and then just the opposite as those folks dispersed into the city.

You could see where the city was pulsating and people movement and flows, Ratti says. That kind of information can be important in planning everything from how to accommodate major events, such as a soccer match, to planning emergency evacuation routes. It also reveals such useful things as where cell handoffs are happening and where infrastructure might be insufficient.

Next up, the lab is trying to determine how a city can work as a real-time system. "Cities are not easy to change other than control traffic lights or reconfigure road lanes," Ratti says. "But people change behavior based on what's going on. You can influence them."

"Cities of tomorrow will be made of concrete and silicon, and will make that possible, but "we don't know how to do that yet," he adds.