from globeatnight.org:

GLOBE at Night is an annual 2-week campaign in March. People all over the world record the brightness of their night sky by matching its appearance toward the constellation Orion with star maps of progressively fainter stars. They submit their measurements on-line and a few weeks later, organizers release a map of light-pollution levels worldwide. Over the last four GLOBE at Night campaigns, volunteers from over 100 nations have contributed 35,000 measurements.

Thanks to everyone who participated in the 2009 GLOBE at Night campaign during 16-28 March! Through GLOBE at Night, students — alongside teachers, parents and community members — amassed a data set from which they can begin to explore the concept of light pollution and to research the patterns of light pollution across the globe. (reposted from www.globeatnight.org)

A record number of over 15,000 measurements were received in the 2009 campaign! See this data on the Map page.

An audio podcast (10 minutes) on light pollution and how to participate in GLOBE at Night:
http://365daysofastronomy.org/2010/02/03/february-3rd-the-globe-at-night-campaign-our-light-or-starlight/

A powerpoint (with audio and written transcripts) on light pollution and how to participate in GLOBE at Night:
http://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=428

More GLOBE at Night 2010 News.