Marble, an Atlas for your Desktop
While looking for some applications similar to Google Earth I bumped into this KDE educational project Marble. Its a 3D Atlas and Virtual Globe application that aims to help students, teachers or anyone, in learing more about Earth, Mars, Moon and Venus. It provides a whole lot of features other than just the Atlas, with an interface similar to Google Earth.
Some of the best things about "Marble Desktop Globe" are:
* It already comes with about 11 MB of offline data, so that offline users are not in loss.
* Even though it shows a 3D view of the Earth it doesn't make use of hardware-acceleration(no Open-GL). This makes it easier to run on various platforms.