The $9 cardboard bicycle Sep 11 2012
Izhar Gafni has designed a bike that weighs 20 pounds, costs between $9-12 to build, can hold up to a 485 pound person, and it made out of cardboard.
Engineers told Gafni that his idea was impossible. Yet he realized that paper could be strong if treated properly. As in crafting origami and tearing telephone books, he explains, "[if] you fold it once, and it's not just twice the strength, it's three times the strength."
The development to what you see today took three years. Two were spent just figuring out the cardboard complications--leading to several patents--and the last was spent converting a cardboard box on wheels to a relatively normal looking bike.
(thx, mickey & erika)