"Geotagged photos, geographically indexed on a world map, either manually or via GPS, are an increasingly popular phenomenon. However, current implementations treat maps, and particularly 3D models, in fundamentally different modalities than photographs. The result is that photos tend to hover like playing cards, seemingly suspended over the world, remaining 2D objects in a 3D environment, and negating the transformative experience that we think should occur when combining images and a 3D world. (...) It's possible to place a photo in a 3D model in such a way that it appears seamlessly aligned with the model."
Google has already bought Panoramio, a Spanish photo sharing site that selected around 3 million geotagged photos to be added in a Google Earth layer. In October last year, Flickr had more than 42 million geotagged photos. All these photos could be used to compose a more accurate representation of the world. Combining this with projects such as Microsoft's PhotoSynth should result in new exciting ways to explore the world.
{ via BoingBoing }
Update: More about Viewfinder in this Google techtalk.