"http://blog.backblaze.com/2009... was an interesting article posted a few months back. It calculated the pure HDD cost purchasing 1 Petabyte of storage at $81,000. This would end up using about a rack and a half of space, depending how high they're stacked. It'll be interesting to learn, if they decide to go through with this, if they decide to utilize hard drives or go with an alternative solution, say tape drives or solid state media." - John Long