1) Welcome to data.org
The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the Executive Branch of the Federal Government. Example: Residential Energy Consumption Survey (RECS). The Residential Energy Consumption Survey (RECS) provides information on the use of energy in residential housing units in the United States. This information includes the physical characteristics of the housing units, the appliances utilized including space heating and cooling equipment, demographic characteristics of the household, the types of fuels used, and other information that relates to energy use.
2) Yahoo! GeoPlanet Data
Yahoo! GeoPlanet helps bridge the gap between the real and virtual worlds by providing an open, permanent, and intelligent infrastructure for geo-referencing data on the Internet.