The worldwide shortage in water is unquestionably one of the most pressing problems we face. The causes are many, the symptoms complex, and the solutions differ according to the context in which they'll be applied, but it is not too difficult to see the water crisis as one large issue with many local faces.
That's why I expect that we'll see a spike in local water solutions around the planet in the coming decade. To get a flavor of what some of those solutions might be like, check out the innovations highlighted in the Wilson Center's excellent overview Water Stories:
[This report] seeks to move past technical “hardware” evaluations by incorporating “software” issues. To ensure the effectiveness and sustainability of water and sanitation projects, the users must support them. Project designers thus must understand how culture and gender issues affect demand and acceptance by the community. As John Oldfield notes in his chapter, “breakthrough practices in [the water and sanitation sector] are rarely new technological solutions,” but are instead those that innovatively and cooperatively apply current technology to meet local needs.
It's a point well-taken, and the report itself is a really excellent summary of the best practices currently found in the field. My only criticism would be that I suspect many of the best emerging solutions -- in water and other fields -- will actually transcend this hardware/software dichotomy to incorporate not only technological innovation and community engagement, but also design insight and systems thinking.
Here is a recent example of a very local solution that transformed a whole tribal village in the eastern ghat mountains in India - with brains brawn, heart and a litle bit of money.
View this few minutes of youtube video: http://www.youtube.com/watch?v=Q81UcGBt28I and NGO is www.samataindia.org