I remember talking about things like this at the Our Visual Landscape conference in 1999 and noting that our impressions of the landscape are not just visual but informed increasingly by outside information.
The Dutch company SPRXmobile has launched the world’s first Augmented Reality browser platform. Layar, currently runs on Android and combines the data from the cellphone’s compass and GPS coordinates identify position and direction. A “radar view” then applies a visual information layer on top of the camera display as you pan around your environment. Later this year there are plans for an iPhone 3G S version.
Currently, and not surprisingly the issue is appropriately constructed and available content. They are working in the Netherlands and UK but this certainly moves the idea forward in a compelling way!