Here is a hanging shelf setup that was on display at the 2005 Abitare il Tempo floor show.

Flying V Shelves

We don't know much about the actual shelves, but they look like a modern, metal design, suspended by 4 small cables. They could be used by themselves, or several in a row to create a room divider. They could even be hung near the celing to produce some convenient overhead storage.

These wouldn't fit everyone's decor, but there are a lot of ways this concept might work in differnet situations.