At an event coinciding with E3, the Electronic Entertainment Expo, but in San Francisco instead of Los Angeles, Google executives showed off the new features, including the ability to select "make available offline" and transfer a file to the device. If data connection is available, the service can pinpoint your location, but turning it off can save roaming charges while traveling abroad.

As a way of differentiating the Android version of this capability, it will allow zooming to StreetView, while the iOS version won't, according to published reports.

Backpack View

Other features, according to reports, include a Map Maker tool to submit corrections in some countries, and a virtual tour guide.

Google is using planes, cars and even people with backpack-mounted 360-degree cameras for StreetView to produce the most detailed maps, an effort that began when the company acquired the startup Keyhole in 2004.

The company posted videos on YouTube Wednesday demonstrating its realistic views of the San Francisco skyline and coast, with engineers noting, "Today, all of us have become explorers," and, "These days, a map is dynamic, it's live, it's personalized to you."

Google said it would "begin adding 3-D models to entire metropolitan areas to Google Earth on mobile devices in the near future."

The 45-degree aerial imagery will allow for 3-D cityscapes with detailed buildings, terrain and landscaping.

"By the end of the year, we aim to have 3-D coverage for metropolitan areas with a combined population of 300 million people," Google said.

The Wall Street Journal, citing unnamed sources, recently said Apple was working in its own map app to replace Google's widely used system as the two companies become increasingly bitter rivals.

'Apple Plays A Long Game'

Pushing out the revamped Google product before Apple is out of the gate with its own app could firm up its standing.

"Apple tends to push pretty hard on their new applications," said technology consultant Rob Enderle of the Enderle Group.

"However, folks don't like to switch , and are likely used to Google Maps. If the Google product is better it'll make switching much harder. Apple will likely get a large chunk of new iPhone users to use Apple's product and then they won't likely switch either. Apple plays a long game. "

Apple has had mixed results with its non-hardware offerings. It's Siri personal assistant for the iPhone 4S is an unqualified success. But its attempted social network built around iTunes, Ping, drew mostly blank stares when it was rolled out in September 2010.

Recommended Reading: Search & Destroy: Why You Can't Trust Google Inc. Synopsis: This is the other side of the Google story. In Search & Destroy, Google expert Scott Cleland, shows that the world's most powerful company is not who it pretends to be. Google pretends to be a harmless lamb, but chose a full-size model of a Tyrannosaurus Rex as its mascot. Beware the T-Rex in sheep's clothing.