• Semacode | URL barcodes | practical ubiquitous computing
  Semacode’s Software Development Kit is a system for ubiquitous computing. Using the Semacode SDK you can create visual tags for objects and contexts, and read them using a mobile camera phone.
  (tags: ubicomp ubiquitouscomputing barcode mobile internetofthings)
• The Kaywa Reader
  Kaywa’s QR (Quick Response) codes are visual tags for objects that can be read on a mobile camera phone.
  (tags: ubicomp ubiquitouscomputing barcode mobile internetofthings)

2007.04.01 update: related NYTimes article by Louise story: “New Bar Codes Can Talk With Your Cellphone”