I once read (IIRC, in a reliable place) that a question park rangers at the Grand Canyon have to deal with is "What tools did they use?". Some visitors are under the impression that the canyon was *built* -- either by the natives, for religious purposes, or during the New Deal, to alleviate unemployment.

Surely, if any such visitors have written books about their beliefs, they should be on sale at the visitor center, right next to the creationist ones. Far from being indignant, I think we should consider, with all due seriousness, the possibility that Providence has created such foolishness in the knowledge that we enjoy being amused as well as being impressed.