The industry is currently addressing this issue.  Currently there exists a
product that will backup changed bits in a document.  It is a slick product
and I think that is the way the industry will be going.  In the old method,
if one has a 2000 page document and you make one change to one page the
backup software backs up the entire document.  With this product, it will
only backup that single change.

The demo I say was pretty slick.

Dave Larimer,
State Farm Insurance