We have been using data to solve problems for millennia. Ancient Sumerian culture used tally sticks to count sheep. John Graunt, a London hat-maker and perhaps the first data nerd, helped authorities fight the bubonic plague in 1651 by collecting data about all the ways people died. (Deaths by Plague: 110. Deaths by Fainting in the Bath: 1.) So, what's different now? With personal technology like the PC, and then the smartphone, combined...