The biggest clearinghouse of third-party content for Google Earth is Google Earth Community, an online bulletin board administered by Google but open to all. Most postings on the board include place marks--links to thousands of KML files that, when downloaded, automatically open Google Earth and "fly" the user to the referenced locations. One recently published place mark, for example, opens a global database of ocean-swell forecasts provided by surfing site Wavewatch.

Bentley Systems, an Exton, PA-based company, provides mapping and computer-aided design software for large infrastructure systems such as roads and power plants. It added KML support to its products this year, in part because Google Earth's simple interface and high-resolution aerial photography can often showcase geocoded data in a more intuitive way than Bentley's more specialized software.

"We can bump our models out to Google Earth, grab the images associated with the landscape for that view, and bring that context back into our CAD environment," explains Joe Croser, Bentley's global marketing director for platform products. "Many people can look at an architectural drawing the wrong way up and not even realize it. But if you give someone a 3-D visual and include photography of the location, it's immediately easy to read."

Is KML becoming a de facto standard for geo-based content? "I think it is," says Google Earth-watcher and blogger Taylor. He also warns, however, that the company's traditional nemesis, Microsoft, may be hot on its heels in the race to provide the most engaging consumer-targeted mapping tools. "They already have Microsoft Flight Simulator, which is basically a 3-D environment for exploring the whole world, using the same terrain data as Google Earth," Taylor says. "I would not guarantee that Google Earth will be alone for long."