Do you like some of the New York Times maps and graphics? If so, you can view some of the projects here. Also, at the bottom of the page is MapShaper, which looks like it could be very useful for simplifying shapefiles for KML use.
The Spatial History Project at Stanford University, a part of the Bill Lane Center for the Study of the North American West, is made possible by the generous funding of the Andrew W. Mellon Foundation.