WorldChanging recently linked to this neat 1957 San Francisco Bay Area Hydrological Model, an actual physical model built by the Army Corp Of Engineers to model hydrology in the Bay. WorldChanging also makes the point that visualizing the hidden infrastructure on which urban areas depend is an important way of understanding urban environmental impact. I've always wanted a mapping tool that tells me where my water comes from, where my power is generated, where my sewage goes, etc. But, uh, that might just be me. Anyone know of some good infrastructure visualizations out there?