>Another way to look at it would be going the other way smaller - nanotechnology - check out articles by Eric Drexler on the net. Tracking billions and billons of 'nano machines' produced by molecular production lines might require exabytes to track 'em....
>
>>>Current estimates of numbers of stars in the galaxy are around 200 billion, so around 80Gb per star in the galaxy.
>>
>>Done it again, 3 extra zeroes this time - that should be 80Mb

http://staff.sdsc.edu/its/terafile/

This site gives details of making a Terabyte file server for $5000, so 16 million of them for a 16 exabyte server should cost around $80 billion, add a bit more space for operating system/indexes/memo file, say around $100 billion. I think their claim is safe at least in the short term against someone testing it to the limit.