Last year, for instance, Pentland's lab put sociometers on 80 employees at a Bank of America ( BAC - news - people ) call center in Rhode Island. The inconspicuous badges used Bluetooth and infrared signals to measure which co-workers the test subjects talked to every minute for a month and, later, another period of six weeks. After the first month the MIT researchers could see that individuals who talked to more co-workers were getting through calls faster, felt less stressed and had the same approval ratings as their peers. Informally talking out problems and solutions, it seemed, produced better results than following the employee handbook or obeying managers' e-mailed instructions.

So the call center tried its own experiment. Instead of staggering employees' coffee breaks as it had previously, it aligned their breaks to allow more chatter. The result, Bank of America told MIT a few months later: productivity gains worth about $15 million a year.

The red balloon victory and the call center experiment also demonstrate that Pentland's sensor studies can do more than fulfill his data fetish. Reality mining can teach us how to change reality. Upcoming projects will aim to encourage better energy use and health habits. "How do you get people to stop smoking or find a lost child? You leverage social networks," says Pentland. "We've studied human behavior, and now we're learning how to shape it."The lesson of the call center is the same one that Pentland's balloon hunters used to motivate thousands of followers to spend a Saturday assembling search posses: create incentives that lubricate information-sharing and teamwork. "The sociometric stuff told us what the facts really are, independent of the sociology and cultural clutter," says Pentland. "And some of the facts are surprising, like the fact that gossip improves productivity."