It is called QR Code or Datamartrix and is essentially a 2D barcode which allows you to loads more of than your traditional 1D (Every day barcodes), into a barcode format, which can be scanned to allow this info to be read.
Most popular at the moment is readers have now become available for Mobile phones. This allows a person to quicly scan the QR code, and then access a site directly from their phone. You can also generate a code to email you, or even SMS you.
Johnson & Johnson have started implementing these codes globally on thier products, that can be scanned with a 2D barcode scanner, which contains vital information, about the product, like Manufactured date, lot number, expiry date etc etc. Some info on it here
A site called Semapedia, have started linking Wikipeida Articles and Data Matrix codes that allow a full page to be printed out and placed next to the object. So for example when you standing outside a museum in London and you want to know the history behind it, you can scan the Data Matrix code with your phone, and it will take you to the Wikipeida Page, and tell you the history
Generating the codes is simple, and there are quite a few sites which allow you to generate these codes and share them.
To download a reader for your phone: Check http://reader.kaywa.com (Most phones including a Java Reader) or http://www.quickmark.com.tw/En/. You can also generate QR & Data Matrix codes on these sites.
I reckon this has a potential to become a whole lot bigger in South Africa & Africa where a vast majority of the population has access to cellphones. I would love to hear some comments and Ideas how this could be used in modern day life.