(Via infosthetics): dencity is very interesting:
denCity.net is an experiment concerning the territorialisation of the virtual and the deterritorialisation of the physical, en route to an augmented perception of urban reality and density. it's about "density", "city", about "den" (which in japanese means "electronic"), and about "nets"...denCity.net creates virtual networks of real places. qr-codes (2d barcodes) are used to tag buildings and urban sites. your mobile camera phone can read these tags. simply shoot them and log in to denCity.net.
denCity.net provides information to the specific place. from there, you can browse through the web of tags. the tag is the key. once shot, you can always return to the places, virtually. it's the city in your pocket. anyone can tag places and thus create a new denCity-site. just log in to denCity.net - create a spot on the map and print the tag to attach it to the real-world location. [until now, the system only supports tag creation in the city of aachen, germany]
The goal of the project is compelling (especially for some folks here)
denCity.net examines the enrichment of real urban sites by a virtual dimension of information and networking, beeing accomplished by localisation of the virtual. it is about moderating between "virtual reality"-networks and the city as physical existence.
There are several ways to visualize the messages (bubbles):
Why do i blog this? the project seems to be innovative in terms of the visualization, I'd be happy to see how it's employed by potential users, and whether they have formal/less-formal scenarios of use that are really deployed (I am always curious/dubious to know how this kind of system are used).