GeoCommons Finder is a great place to find publicly shared data sets for use in KML files (Google Earth file format). GeoCommons Maker provides users a quick and easy way to take the datasets found in GeoCommons Finder and display those datasets on a map. Users can create multi-layered maps and customize the way those layers are displayed.

The video below offers a brief overview of how to create maps using GeoCommons Maker.

A product similar to GeoCommons Maker that you may want to try is the Thematic Mapping Engine.

Applications for Education
GeoCommons Maker is as easy, if not easier, to use as Google Maps. The benefit of using GeoCommons Maker is that students can find datasets without having to search the Internet for them. This should save time when you’re trying to complete a lesson plan in one sitting. GeoCommons has datasets that are relevant for use in Social Studies, Math, and Science.

Update: as was pointed out in the comments, maps made in GeoCommons Maker can be embedded into a blog or website.