Just found this site. Anyone who lives in Missouri, USA, might find it interesting. I've only looked at maps for St. Louis County; they show roads (but not road names), general indications of percent of grade, topo countours, all sorts of other data. I checked the slope of some hills I ride, and now I don't feel so bad about how slow I climb.
Edit: Contour data is incomplete. Some sections show it, and some do not.