"In one window on my computer, I'm strolling down the Embarcadero in San Francisco -- but instead of sticking to the sidewalk, I'm somehow occupying the middle of the southbound lanes, where I've been passed by a series of sport-utility vehicles.

In another browser window, I'm flying over a slightly blurry version of Lower Manhattan. I can see the park near my cousin's old apartment, but I can't spot the pizza joint or the bagel store that should be there. Then again, I can get uptown much faster than usual, since I'm no longer confined to the streets or the subway.

Online mapping has advanced a little since the days when everybody was excited just to see Web sites that could calculate driving directions for us.

Now, mapping sites include extras like satellite photography, real-time traffic data and outlines of buildings. They even act like regular desktop programs, allowing you to scroll around and zoom in with a keyboard or mouse -- no need to wait for a page to reload.

This week, the operators of the two best mapping sites -- Google and Microsoft-- upgraded their mapping sites in flashy, useful ways.

Google Maps now provides a "Street View" option -- pavement-level perspectives of Denver, Las Vegas, Miami, New York and San Francisco. Microsoft's Live Search Maps, meanwhile, has expanded the list of cities in which it provides three-dimensional flyover views to include New York and other U.S. and international locales, such as Austin and Ottawa.

These options are not quite new. Google's Google Earth program offers its own 3-D flyovers, though without the high resolution of Microsoft's service. Amazon's A9 search site provided a sidewalk-view option years ago, and Microsoft has a version of that concept tucked away on a corner of its own site .

But now you don't need to bookmark a new site or run a separate program. You can open your Web browser to a mapping site you already know and start clicking away.

Google Maps' Street View doesn't require any extra software; it worked in the Internet Explorer, Firefox and Safari browsers. If this option is available in the area you're viewing, a "Street View" button will appear. Click it, and any streets with available photography will appear outlined in blue. Then drag a stick-figure icon to the street you want to inspect.

The Street View vista appears in a little frame over the standard Google Map view. You can pan around the view or zoom in just by scrolling or double-clicking. Then, wander through the city by clicking the arrow icons that float over each street.

It may remind you of navigating through old interactive-adventure games like Myst, except all this runs inside your Web browser, not a CD-ROM's worth of separate software.

Street View photos sometimes had the washed-out look of camera-phone pictures but still yielded an extraordinary level of detail -- I couldn't read headlines in newspaper vending boxes, but I could easily make out the license plates of cars on the streets.

Microsoft's 3-D feature takes a lot more work to try, unfortunately. It requires you to install a plug-in for your browser -- Internet Explorer or Firefox for Windows XP or newer only -- and also demands a reasonably powerful graphics card with the right driver software already on board.

That software was absent on my machine (something I had to guess from a vague error message displayed after the first install attempt failed), and so I had to find the right driver off Dell's site, install that, restart, and then try the 3-D software install again.

Microsoft's installer compounded the annoyance of this procedure by trying to change Internet Explorer's home page and search-engine settings.

This plug-in software eventually worked, providing that Superman (or perhaps Spider-Man) feeling of swooping over Manhattan. But the entire computer ran as if concrete were clogging its gears anytime I tried switching among open applications.

Both of these new features make the other big mapping sites, Yahoo Maps and AOL's MapQuest, look sorely out of date. And though both can provide a crowd-pleasing demonstration, they have legitimately practical uses. Even overhead satellite views can't suffice to show you what the view might be like from a given house location, or how pleasant the walk might be to a nearby restaurant or shop.

Google and Microsoft's competitors will have to offer something comparable to stay relevant. The competition between these two rivals, meanwhile, can only get more interesting -- which one will be the first to provide some of these new viewing options on a cellphone or, better yet, on a car's navigation screen?" (Rob Pegoraro, The Washington Post, May 31, 2007)