With the help of some pretty funky technology, millions of people are zooming through space, flying over continents and climbing mountains—all from behind their PCs. Kind of like the globe you had as a child, virtual globe technology gives a visually accurate, 3D representation of the Earth.

Virtual globes are quickly changing the way we deal with spatial data and are transforming our ability to visualise the world. Showing graphical and man-made features, virtual globes have the advantage of being able to visually represent many different views of the earth’s surface.

To add to that, today’s numerous virtual globe applications are capable of rotating, zooming and tilting. Connected to satellite image servers, they even provide additional data such as roads, political boundaries and other basic image overlays. Some even have GPS integration.

Those of you who have played with Google Earth have experienced virtual globe technology—and probably found how helpful and even fun it can be. Coined in the NY Times as an application for “anyone who has ever dreamed of flying,” Google Earth is by far the most popular virtual globe technology with over 12 million downloads of the software.

Google Earth lets users zoom in and explore almost any place on the planet. Users can view school and parks, get driving directions or even fly over your next aeroplane route. In addition, Google Earth features 3D buildings in major cities and 3D terrain showing things like mountains and valleys.

Combining satellite imagery, maps and Google search technology, Google Earth is available with one simple download for personal users—commercial users must pay a fee. Terabytes of aerial and satellite imagery show cities around the world. Google has hired chartered flights to take aerial images over many US cities. Not all of the world is in high enough resolution to see individual cars and buildings, but Google is continually adding this high resolution coverage.

But Google isn’t the only virtual Globe, and certainly not the first.

SINTEF Virtual Globe was released in 2001 and one of the original ‘modern day’ virtual globes. It’s a 3D globe viewer with elevations and satellite images that works as a client server application for displaying terrain modules. To try the globe, users need to install the latest version of Java, either 1.4 or 1.5. Using a mouse or keyboard to shift viewing angle and areas viewed, SINTEF’s Virtual Globe offers a number of java-based demos of the world and even Mars.

One of the newest and most cutting edge versions of consumer virtual globes in production right now is Windows Live Local. The preview available at http://preview.local.live.com/ demonstrates Microsoft’s work-in-progress thinking about a ‘rich immersive experience in mapping’. The technology lets users walk or drive through the streets of Seattle or San Francisco. Moving through the streets, photos seamlessly guide users like they were actually physically present. A bird’s eye view helps users get an overall sense of where they’re going.

Powered by VirtualEarth, search boxes help users find places of interest while zoom features allow them to zoom in and out. But it will likely a long, long time before Microsoft has the world virtually mapped as well as the others. Already 700 million high-resolution images have been taken in Seattle and San Francisco alone, which equals some 200 terabytes of data. Mapping the world will prove to be no small feat.

Too bad they couldn’t figure out a way to actually physically transport us. But that’s a whole new can of worms…