Wikipedia no longer has an entry for physical world hyperlinking - its been superseded by object hyperlinking! Personally I like the term physical world hyperlinking better. Object hyperlinking sounds very dehumanised. They've now updated the entry  contain more detailed information about such practices and include the term "tagging" as a collective noun, which has been broken down into groups such as RFID, Virtual, text based, SMS and Graphical. So as the ground shifts, nomenclatures are emerging and according to the most current wikipedia update,  my investigation is now into graphical tagging. Interestingly enough wikipedia hasn't got a conclusive list of all the types of graphical tagging out there.

 
One type of tagging  that looks quite cool is Shotcode, which was developed by Cambridge University. They are not as prolific as QR-codes and I am not sure what the future for them is, but the artist in me says" hmm... they look pretty", which no doubt is too flippant for many tecchies, but ultimately if you want people to use the technology you develop, you've got to make it appealing.... and currently much of it is so user-unfriendly it is not at all appealing. On the left is the shotcode tag for my blog, and the reader does seem to support a much wider range of mobile handsets than the i-nigma reader for QR-codes does.