Conserving the Night Sky
Is your portion of the night sky polluted by artificial light? Check out this really slick Google Map interface I found on the International Dark-Sky Association (IDA) web site . For over 22 years, the IDA has been advocating to keep our night sky clean of light pollution. Their reasons go beyond astronomy purposes and have provided resources for legislation that would both reduce night sky lighting and provide very large amounts of energy savings to the global economy.
Data for the map comes from the NGDC, where you can find some links to more interactive maps and other imagery services.