Among them, Google Maps now includes a "Street View" option that shows you a street-level photo of any point on a map, like this one of Radio City Music Hall in New York City. It is using technology from a cool startup called Immersive Media to do this. (Amazon's A9 search engine pioneered this concept of marrying maps to real-world pictures, but it never went anywhere because nobody ever used A9).
A startup called EveryScape is trying something similar. It shows a Google map on the right and a navigable digital photo montage on the left. Anywhere you move on the map, you will see what that place actually looks like in the picture. (EveryScape just launched today, and only has a limited preview covering Union Square in San Francisco, but is working on adding the entire city, as well as Boston, New York, and Seattle).
I find the application to be a bit too slow when you are trying to navigate through the photos instead of on the map. But EveryScape is experimenting with some interesting concepts, such as placing clickable buttons on buildings that bring up a store's URL. Or making it possible to zoom into a building and see what it looks like from the inside.
As if photo-map mashups weren't immersive enough, Microsoft Live Maps is turning photos into 3-D landscapes you can fly through (image via TechCrunch). And Google is expected to add similar functionality soon from technology it licensed from the Stanford robotics team that won the DARPA Grand Challenge of sending a self-driving car across the desert.
Who needs Second Life when the real world is being digitized and put on the Web?