Someone else does work that you got hauled off once you've made some useful pre-studies...
Mobile phones expose human habits
By Jonathan Fildes Science and technology reporter, BBC News
People's movements were not as random as predicted
The whereabouts of more than 100,000 mobile phone users have been tracked in an attempt to build a comprehensive picture of human movements.
BBC news story
"It would be wonderful if every [mobile] carrier could give universities access to their data because it's so rich," said Dr Marta Gonzalez of Northeastern University, Boston, US, and one of the authors of the paper.