Softbank and Aoyama Gakuin University know the Japanese. Probably because they are Japanese. They know that the Japanese use their phones for everything: mail, gaming, banking, oh, and sometimes phone calls. They also know what the Japanese may use their phones for: tracking disease.
A group of 1,000 students will be given iPhones (luckiest students ever says this 3G model user), and their attendance will be tracked via GPS. A few months from now, some of these students will be hit with a virtual disease. Given the nature of Japan, a virtual form of swine flu would hilariously ironic. Following this, their movements will be tracked via GPS to determine which children have crossed paths. The families of exposed students will be notified via cell phone messages with instructions on how to get them checked out by doctors.
Softbank throws out this situation: if one person were to spread their disease to three people a day, by the 10th day, 60,000 people would carry the disease. But, in contrast, if that interaction is limited to two people a day, only 1,500 would be carriers of the disease. Knowing who has what would surely go a longer way towards preventing an epidemic than those silly face masks.
You know what knowing also is? Half the battle.