In the late 90s, when I lived in New Hampshire, I used to cross paths with the pilots at DHART http://www.dhmc.org/dhart.cfm

As I recall, they were building their own database of hospital helipads (or parking lots), ski areas, intersections and other possible landing zones in their service area. At one point I think they even drove around on their days off to take fixes. That is some serious dedication. And smart.