Almost 160 billion GB of data were generated in 2006

When tech analyst John Gantz at researcher IDC began tallying up all the digital information generated annually, he first looked in the obvious places.
He counted e-mail, spreadsheets and the other data collected by most corporate computer systems. Then there was the new digital data created by consumers. (Take digital cameras: More than 32 million are expected to be sold this year, says the Consumer Electronics Association trade group.)
But then Gantz realized that he had to look deeper. Digital photos aren't just snapped by traditional cameras — they're also taken by millions of security cameras and camera cellphones, for example.
Gantz ultimately calculated that 161 exabytes of digital data — or about 161 billion GB — were generated in 2006. And the amount is expected to rise fast.