In Japan, these black and white squares with dot patterns are absolutely ubiquitous. They are in magazines, printed on packs of toilet paper handed by young women, on billboards, etc. You use your phone’s camera to read the image, and it converts into a URL or phone number.
http://www.denso-wave.com/qrcode/index-e.html
To reach this blog scan this in with a QR reader:
QC decoder/encoder library for Java:
