1.2 zettabyte of data
OK, so I was a bit slow to discover this, but The Economist has a special report on big data which is freely available online. That is, the individual articles are free, and a PDF compiling them is supposed to cost 3 GBP, but I was able to download it for free here without doing anything special.
A fun fact that I learned from this report is that the total amount of information in the world this year is projected to reach 1.2 zb (zettabyte) – which is 1.2×10^21 byte. How on earth did they come up with that figure…? Anyway, this report is worth a read, as it touches on things like business analytics, web mining, open government data and augmented cognition, while also giving some well deserved love to R and open source software.