I'm very much inspired by the possibilities suggested in Mapping Sebald's Literary Landscape, which links to Barbara Hui's "Litmap" - an annotation of Google Maps with the places mentioned during the East Anglian walking tour of the unnamed narrator of The Rings of Saturn.
See her Litmap Presentation Notes for background. The notes mention a similar project, Gutenkarte, that mines Project Gutenbeg texts to create presentations with placenames hyeprlinked to a map. It has rough edges - for instance, it thinks Providence might be a location in
they had a notion that Providence would interfere in favour of him who was in the right.
- The Journal of a Tour to the Hebrides with Samuel Johnson, LL.D., James Boswell
but it seems a very good interface for reading works with a strongly geographical component.