The Cellphone, Navigating Our Lives – NYTimes.com:

Indeed, a new generation of smartphones like the G1, with Android software developed by Google, and a range of Japanese phones now “augment” reality by painting a map over a phone-screen image of the user’s surroundings produced by the phone’s camera.

With this sort of map it is possible to see a three-dimensional view of one’s surroundings, including the annotated distance to objects that may be obscured by buildings in the foreground. For starters, map-based cellphones simply translate paper maps into a digital medium, but future systems will probably begin to blur the boundaries between the display and the real world.

“I always said the next interface would be Quake,” said Steve Capps, one of the designers of the original Macintosh interface, referring to the popular video game. “How long will it be before you come out of the subway and you hold up your screen to get a better view of what you’re looking at in the physical world?”

And will mobile mapping handicap brain development?

“Humans evolved with amazing navigational abilities in our brains from an evolutionary perspective,” said Eric Schmidt, Google’s chief executive. He argues that the correlation between the map on the phone and the internal map in your head is a natural way to navigate all kinds of information.

For example, neuroscientists have discovered that people who have occupations that require them to maintain complex mental maps of the world, like London taxi drivers, have an enlarged hippocampus. What happens when our hand-held computers become extensions of the way we think?

“I have wondered about the fact that we might as a culture lose the skill of mapping our environment, relying on the Web to tell us how to navigate,” said Hugo Spiers, a neurobiologist at University College London. “Thus, it might reduce the growth of cells in the hippocampus, which we think stores our internal maps.”