You can tell a little bit about what part of the country you're in by the sundaes on the menu.
In Keene, N.H., you can get a rather austere-sounding fruit-salad sundae, which is not something you can imagine ordering in, say, Texas. In Foley, Ala., there's a chocolaty-thick sundae called Lower Alabama Mud. And In Las Cruces, N.M., you can dare to order the green chile sundae: vanilla ice cream laced with spicy-sweet green chile marmalade.
Michael Turback, author of More Than a Month of Sundaes, lists 365 purveyors in all 50 states. He calls them the "cream of the crop," notable for their "versatility, creative achievement, construction technique, and respect for tradition." Read the list (PDF).