IDC estimates that 161 Billion Gigabytes, or 161 exabytes, of digital information was created and copied worldwide in 2006. The report creators say that is roughly equivalent to 12 stacks of the latest Harry Potter novel, each reaching from the earth to the sun.

But how many hard drives is that?

Read here (http://www.digitalhome.ca/content/view/1733/1/) for the answer