I am posting this from an email I got from Mike in Cambodia. I thought you guys would have more knowledge of this than I would. Of coarse I am referring to Gary and David.

My wife and I are welfare missionaries for the Mormon Church in cambodia. We are involved with clean water projects. We were just funded $50k for a project and have another just like in the approval process and will have 2 morein 2006.
We have several problems we are dealing with, the first being our lack of knowledge about pumps and wells.
We are mostly doing pumps/wells for clean drinking water. We are also looking at rain collection for drinking water and what would be the most efficient, inexpensive way to do that.
We are also looking at irrigation water in rural areas where there is no power. We have talked about solar power but we also have talked about cow/water buffalo power using some sort of rotary pump that could be turned by an animal being walked in a circle. Any help or other ideas would be appreciated.
Thanks. Mike