"Water, water, everywhere, and not a drop to drink," wrote Samuel Taylor Coleridge in 'The Rime of the Ancient Mariner'. And as you look at our planet from space there is water everywhere. But in many parts of Africa there is not a drop to drink.

Enter stage right: Amisadai and Louisa. Two enterprising young girls, if a grandfather may be permitted to say that of his 10- and 7-year old grand-daughters living in Tanzania. Children with a mission.

They have been blogging about their life as missionary kids for a few years at "Amaisadai and Louisa's Adventures in Africa". But now they have a new adventure and have started another web site to focus on water.

But first a two minute video. Here are the girls working on a very simple project with water that can help to save lots of lives that are lost through poor hygiene in Africa. It's called a tippy tap. All you need is 4 sticks, 1 bottle, string, a shovel, a candle and a nail. See how it's done!

I hope you are feeling suitably inspired! In which case, here is more of what they are up to and ways in which you can help.

If you go to their new web site, mongergirlswaterworks.webs.com you will discover how to purify water in places like Africa without any equipment. And to show that anybody can do it, Amisadai and Louisa do it.

Make sure you click on the Sodis shake" link on their web site, where the video came from, and there you can read all about it. Then you can help! They are embarking on a sponsored shake and a Water Walk. The details are all on their new website. There's a whole lot of shakin' going on!