Today, March 22nd, is recognized by the United Nations Water Group as "World Water Day", this year's theme being "Clean Water for a Healthy World". Although we live on a water-covered planet, only 1% of the world's water is available for human use, the rest locked away in oceans, ice, and the atmosphere. The National Geographic Society feels so strongly about the issues around fresh water that they are distributing an interactive version of their April, 2010 magazine for download - free until April 2nd - and will be exhibiting images from the series at the Annenberg Space for photography . National Geographic was also kind enough to share 15 of their images below, in a collection with other photos from news agencies and NASA - all of water, here at home - Earth. ( 43 photos total