I think that's officially the Big Change, and it's already happened, rather than being ahead.

So what might still happen?

The dialogue with the map is becoming much more personal. You can imagine that in the future, if you have a wearable computer, the dialogue will become even more intimate: you will see a continuous stream of guidance and information, and no one else will even know that you're being advised.

For instance, right now people walk around looking at directions on phones. In the future, the phone will signal you--go left or straight ahead--in words or sounds in your ear, or

visually through your glasses, so you can just look where you're going and walk. It'll be like you're a local everywhere you go. You'll know your way through the back alleys and hutongs of Beijing, you'll know your way all around Paris even if you've never been before. Signs will seem to translate themselves for you. This kind of extra-smartness is coming to people. Effectively, people are about 20 IQ points smarter now because of Google Search and Maps. They don't give Google credit for it, which is fine; they think they're smarter, because they can rely on these tools. It's one reason they get so upset if the tools are inaccurate or let them down. They feel like a fifth of their brain has been taken out.

Isn't this just like the voice in the car GPS telling you, annoyingly, where to turn?

It's more. The Google "geo" team grew from two seeds---Keyhole, which led to Google Earth, and two brothers who founded what is now Google Maps. We've worked to invent the most comprehensive, authoritative, useful mapping solutions that humans can build, and I think we've been pretty successful at that. So I would consider this like Dr. Johnson's compilation of a dictionary of the English language, or maybe the rise of the encyclopedia. It's the creation of a universal reference work, reflecting a lot of labor and great expense, that everybody can rely on.

If you think about Dr. Johnson's dictionary from the point of view of English literature, you might say, "Well, Johnson--he did a dictionary." But what else could you do with words on a piece of paper? Maybe you could write mysteries, or comedy, or adventure stories. You can do a lot of things with the words in his dictionary.

We think there will be a new literature from the mapping dictionary that's now being built. There's an Android app we've released called Field Trip. You download it, and it says, "I don't want to bother you, so how often should I talk to you?" You tell it "all the time" or "rarely" or whatever, and then you turn off your phone and put it in your pocket and don't think about it again.

Then when you're walking around, say in Washington, D.C., the phone will buzz and say, "You are 25 feet from an accurate map of 2,700 solar objects. If you go over there to the Einstein Memorial, you can see them." Or you might be walking down the street and it will beep and say, "The rowhouse one block to the left is the No. 1-rated Greek restaurant within 500 miles," or maybe: "Around the corner behind you is where a scene from your favorite movie was filmed." It is using your location to search in a database of "interesting things," and it learns what kinds of things you care about. It means having your life enlightened by travel knowledge, every-where, or getting to walk around with local experts who know your tastes, wherever in the world you go.