Dr Mark Wright of the Informatics Dept. at the University of Edinburgh in Scotland has built a service that allows users to point and shoot their digital camera phones at structures in and around Edinburgh and send the photos to a centralized local database of superimposed virtual art. The service then renders the superimposed multimedia image back to the users mobile device. Dr Wright is hoping to repurpose the Microsoft Photosynth-like application as a way of adding context presence to blogs. All of this sounds candidly similar to Nokia's MARA [Mobile Augmented Reality Applications] R&D project which is theoretically the closest thing I've seen to a Tricorder.