Matt Jones's invention of warchalking back in 2002 was a lark. It combined the culturally laden notion of chalk signs made by hoboes with the modern nomadic lifestyle of the digerati. As packs of laptop wielders roamed from place to place, a warchalk indicating an open Wi-Fi network would allow those network grazers to stop a moment, and fill up on protein-rich memes.
It was a good project, something that dwelt in the space between meme, prank, and urban near-myth. (I believe BoingBoing has a set of gleaming towers reaching to the sky in that space.) But it didn't become self perpetuating. You can see its remnants in the iconography Jones and others developed for open and closed Wi-Fi networks, which were adopted and used in signage and company logos. The reversed parentheses )( for an open network were particularly brilliant, as it requires no graphics program nor keen hand to type or draw.
I propose that QR_STENCILER and QR_HOBO_CODES are warchalking's direct descendants. I've had a multi-year obsession with QR Codes, one form of two-dimensional tags that can encode information densely in a rectangle for recovery through image capture on a mobile or other device. Snap a picture of a 2D tag with the right software–available for free or fee on nearly all smartphones and many feature phones–and the dots and shapes are translated into text, a URL, or other matter. (See this BoingBoing piece from November 2010, for instance, which explains how to generate QR Codes from a bookmarklet, among other information.)
The QR Code project from Free Art & Technology (F.A.T.) is quite charming in its combination of trends, technology, and cultural markers. Like warchalking, the project takes off from hobo signs, which date back over a century–read this lovely account from a 1904 New York Times story. Hoboes would chalk a code to indicate whether one could get a handout, whether there were dogs, and other knowledge to pass along to the next traveler.
F.A.T. created a set of a 100 signs encoded as text in QR Code format (QR_HOBO_CODES), donated to the public domain, and ready for use in its QR_STENCILER software. The software for Mac OS X creates a laser cutter ready file, including coping with the difficulty of making a stencil of symbols that can have floating squares in empty fields. Tricky stuff, and their images make it look like they've figured out the right approach, although parts of these stencils will certainly be fragile. (The software is licensed under Creative Commons for non-commercial use with attribution on share-alike basis.)
QR Codes and other 2D tags are resilient to fairly major distortion. It looks from the code previews that F.A.T. chose a small size over adding more error correction, which increases the number of symbols necessary. That should be fine in practice, as a lack of distortion, clear edges, and contrast are the most important elements for tag interpretation.
The likelihood is that QR_HOBO_CODES will be just as long lasting as warchalking signs, in that they may affect the culture, but not be used much in practice. I pray to his noodle-y majesty that I am wrong about that, but I've seen the memes come and go.
QR_STENCILER could pack more impact, both in making it easy to create and use such 2D tag stencils–the makers suggest a chalk spray, by the way–and encouraging those frustrated with its inevitable limits to create their own software. In fact, I wouldn't be surprised to shortly see templates for using 3D printers to make stencils that produce 2D tags.
(Thanks to Ren Caldwell!)