Whole lotta bits 'n bytes

I recently bought a pair of 250GB hard drives for my computer. At first it seemed like a tremendous amount of storage capacity, but now I'm not so sure.

There's probably a computer law out there which states something about storage capacity and a user's unfailing ability to fill it up in short order. Thankfully, hardware manufacturers keep pushing the envelope when it comes to expanding the limits of data storage.

Here's a list of data storage units and their approximate storage capacity:

• 1 byte: A letter
• 10 bytes: A word or two
• 100 bytes: A sentence or two
• 1 kilobyte 10³: A very short story
• 10 kilobyte: An encyclopedia page (perhaps with a simple picture)
• 100 kilobyte: A medium-resolution photograph
• 1 megabyte = 10⁶: A novel
• 10 megabytes: Two copies of the complete works of Shakespeare
• 100 megabytes: 1 meter of shelved books
• 1 gigabyte = 10⁹: A pickup truck filled with pages of text
• 1 terrabyte = 10¹²: 50,000 trees of paper
• 10 terrabytes : The printed collection of the U.S. Library of Congress (which consists of 130 million items on about 530 miles of bookshelves, including 29 million book, 2.7 million recordings, 12 million photographs, 4.8 million maps, and 58 million manuscripts).
• 1 petabyte = 10¹⁵: The Internet Archive Wayback Machine contains almost 2 petabytes of data and is currently growing at a rate of 20 terabytes per month; and as of October 15, 2005, all the files being shared on Kazaa totaled around 54 petabytes.
  
• 1 exabyte = 10^18: Berkeley studies estimated that by the end of 1999 the sum of human-produced knowledge (including all audio, video recordings and text/books) was about 12 exabytes of data. The study also estimated that "telephone calls worldwide on both landlines and mobile phones contained 17.3 exabytes of new information if stored in digital form", and "it would take 9.25 exabytes of storage to hold all U.S. [telephone] calls each year." International Data Corporation estimates that 161 exabytes of digital information were created, captured, and replicated worldwide in 2006.
• 1 zettabyte = 10^21: The IDC estimates that by 2010, there will be 988 exabytes, just under a zettabyte, in all computer storage world wide.
• 1 yottabyte = 10²⁴: IBM estimates that soon after 2010 the volume of online data accessible either on the Internet or on corporate networks is expected to approach a yottabyte, or 1 trillion terabytes.
  

That's a lotta data.