You can search for content created by Google Earth and Maps users. This KML-based content offers some of the most exciting material you can see in Google Earth. For great user content, you can also visit the Google Earth Gallery and of course the Google Earth Community.
To search for user content, navigate to an appropriate location and search. User content appears at the bottom of your search results in a folder entitled Web Results and in the 3D viewer as blue markers (see below).