We live in the future. Proof, from MAKE magazine, is a tiny bike that manufactures can print out from layers of nylon powder:

The Airbike is made of nylon... and requires no conventional maintenance or assembly. It is 'grown' from powder, allowing complete sections to be built as one piece... to rider specification.
  • "The Airbike is made of nylon... and requires no conventional maintenance or assembly. It is 'grown' from powder, allowing complete sections to be built as one piece... to rider specification."
Also, if you're the kind of nerd who likes printable bikes, may I also interest you in this interactive chart of public transit, bike, and car commute rates by city? Comparing medium and big-size cities, New York comes out on top as the heaviest users of public transit (54.6 percent), while Portland ranks the highest in the "taxi, motorcycle, bike, or other" category (5.6 percent... though it's clearly old data). What sad folks drive alone to work the most? People from Chesapeake, Virginia.

h/t to Grist!