Just been in a whisper suite here at IBC and saw a very impressive presentation of the storage we'll all be using in 5 years time.  Invented by the guy that did MiniDisc for Sony (now working for his new company, Optware), the medium records lots of tiny holograms onto an polymer substrate.  I remember being into holograms as a child.. in those days you needed 5 tonnes of concrete to prevent vibrations from distorting the images.  There are both DVD style discs and cards.  Check out Optware's site for more.