The Environmental Protection Agency has a simple, easy GIS program called EnviroMapper. The program operates within the web browser so there is no required downloads. With an easy customizable one click interface and selectable layers one can easy check out environmental hazard points around their homes and obtain information about the possible threat. A nice treat is the ability to print the map in a printer-friendly format.
Combined with EarthTools any internet geographer has some powerful tools at their ready.