It is amazing how creative one can get with just cardbox. Here are a few examples of how you can turn a piece of corrugated cardbox into something quite unexpected.

 Cardboard blankets by 
Diane Steverlynck

 James Roberts' cardboard hangers available 
here.

 A business card on a piece of cardboard.(via 
allgraphicdesign).

 BioTube Bench by 
Julian Lwin. (via 
Inhabitat)

 Installation made from honeycombed cardboard panels and rolled up fabric by 
CJ Lim/Studio 8 Architects at the subway entrance in London. (via 
Dezeen)

Cardboard office by French artist 
Paul Coudamy. (via 
Dezeen)