United Nations Children's Fund (UNICEF)

http://www.unicef.org/wes/
UNICEF works to help children gain access to safe drinking water all over the world, both emergency and long-term. Since 1990, the United Nations agency has given 816 million people worldwide the gift of fresh water. A $1 donation can provide 20 litres of clean drinking water; $200 "provides a handpump to supply an entire village with clean, safe water"; $1,000 buys a share in a borehole.