Earth Knowledge, a well-known information technology firm, has recently released their "Earth Knowledge Portal", an impressive collection of data that is tied together using the Google Earth Plug-in. While the site has a variety of different features, the best one is likely their virtual globe. From there, you can view a massive variety of information, including Google Earth Tours, recent earthquakes, geological information, aquifers and rivers, and much more. It's quite an impressive tool. Many of the tours were contributed by the Google Earth Outreach Team, and data has also come from sources including BBC Earth, World Wildlife Fund, Reuters, NASA, NOAA, Christian Science Monitor, and the Global Heritage Fund.
