Water- for the most vital of all natural resources, we sure do waste a lot of it. Many people all over the world do not have clean drinking water, or water for other necessities that we take for granted. More people have mobile phones than clean drinking water... which is a giant problem. I did a project on toilets in Africa, which opened my eyes to the water problem.
Many people (like Matt Damon) have organizations that strive to give everyone access to clean water and sanitary bathrooms. (Check out Water.org for more information) The Bill & Melinda Gates foundation has a contest where people design a new and innovative toilet that can benefit areas that don't have a lot of water. (Here is a link to the contest: Re-inventing the Toilet)
Remember- you can help people by giving to these foundations!
