Move-It. A James Dyson Award winner.

“Move-it is a simple kit of self-adhesive cardboard parts, which the user sticks on to a cardboard package, turning it into a lightweight, easy-to-use trolley. It consists of a set of wheels and two different types of handle. A combination of these components allows the user to move boxes of almost any size and shape up to 20Kg.” (via http://greenopolis.com/)