Google Earth is a virtual globe application, that you can use to view the Earth, either as a satellite image, a series of aerial photographs, or a superimposed combination of the two.
When sorting your photos in Picasa, you can automatically add Geotag information to them, by using Google Earth to locate the exact position on the globe where to photo was taken, and in this screencast tutorial, we show you how.
Once you've uploaded your photos to Google Earth, other users will be able to view your photos, simply by clicking on the tag you created.
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