Remember the good old days when a gigabyte was considered a lot of space? Improvements in hard disk technology have allowed the humble magnetic drive to reach the dizzying heights of multiple terabytes of storage, but Cisco foresees a future that's a few orders of magnitude more impressive. Pinpointing 2015 as the commencement of what it calls the zettabyte era, the company has put together a handy infographic to show us just how much data can be fit into one: you can alternatively think of it as the equivalent of 250 billion DVDs, 36 million years of HD video, or the volume of the Great Wall of China if you allow an 11oz cup of coffee to represent a gig
