"Gee, I wish I'd thought of that!" How often do we think it? As easy as it can be to get down-hearted about the state of our industrialized world, engineers are doing many simple, elegant, much-needed things for their fellow human beings by harnessing technology in a way that demonstrates awareness and expresses compassion. Take a look at this astonishingly simple idea that is bringing pure drinking water to the desert city of Lima, Peru.