Against the advice of his engineer friends, Israeli inventor Izhar Gafni built a working bicycle out of cardboard. He's now ready to make some money out of his invention. A neat story of how somebody smart and persistent can create something compelling out of something we take for granted.
Check out his promo video:
http://vimeo.com/37584656#
If you can't wait for a cardboard bike, perhaps you might want to build your own bamboo bike:
http://www.instructables.com/id/How-to-Build-a-Bamboo-Bicycle/