Large-scale distributed sensors – particularly for things like weather and traffic. Nearly everyone carries a phone that if it isn’t already GPS-enabled, can approximate its location via tower communication. Why can’t I opt to have data automatically collected by my phone used anonymously to give better weather forecasts or traffic conditions? Beyond the practical, economically useful, and potentially lifesaving benefits of this type of data, it would really help me to know when there’s enough wind at the beach to go kitesurfing and not much traffic in the way.