For a couple months, I've been reading about a cardboard bike being developed by a guy in Israel. (Thanks to my friend Bob T - he noticed it, too, and emailed me a link to that particular article.)
A cardboard bike may not hold much appeal to somebody who rides a sweet carbon-fiber or steel, or even aluminum bike... but to some impoverished person in a third-world country, a bike that can be produced for "$9-12 a unit," it might look much better than walking, or riding atop a burro or water buffalo.
And, when you're riding your cardboard bike, you can protect your noggin with a cardboard helmet! A startup company, Kranium, hopes to market them. Apparently they provide better protection than the ubiquitous styrofoam-based buckets. And interestingly, a custom fitting is part of the package... the thing is built to match up perfectly with the shape of your head. (Making it a little spendy at around $130. But a replacement would be cheaper, assuming the reason you need a replacement didn't also re-shape your skull!)
When I first heard about the cardboard bike and helmet, my first thought was - water damage. But apparently the cardboard can be treated with stuff to make it waterproof.