I kind of like this video from YouTube about charity water. It puts the message very effectively.

A little description:

More than 1 billion people on the planet don’t have access to clean drinking water. For $20 a person, non-profit charity: water funds clean water solutions like shallow wells, deep wells, rainwater harvesting systems, and spring protections to provide people in need with clean and safe drinking water. Find out how you can help give one person clean drinking water at charitywater.org