I don't usually do this, but I came across something at a site I check occasionally, Inhabitat, which covers innovations in environmentally-friendly design. They find some really creative stuff from all around the world. This particular idea I thought was worth passing along.
An Australian company called Unicraft Joinery has come up with a way to make storage space out of stairs. Apparently the idea is not new, but I still think it's ingenious. The comments about this particular concept are additionally enlightening and entertaining.