As well as being able to compare prices of stuff in the shops with a quick scan of the QR code, you can create artworks, as artist Scott Blake has shown with his series of famous faces.
A big artwork of Elvis' face comprised of QR codes can be read by a smartphone, linking the user to music by the one and only Mr Presley. Blake also uses other types of barcodes for his famous faces - for example, Bruce Lee and Marilyn Monroe are made up of barcodes from DVDs of their movies, and Oprah's beaming face is created by ISBN barcodes from the Oprah book club. A message about commoditising celebrities, or just a really neat art idea? [Scott Blake via Illusion via DudeCraft]