JungleThingy is a very simple to use Google Maps based search engine for travel guides listed on Amazon.
To search for a travel book for a specific location on JungleThingy just click on a location on Google Maps. The travel guides and travel books for that location are then listed in the middle column. If you then click on one of the listed books you can get further details, including the price, reader ratings and a summary of the book's contents.
GuidebookPlus - maps the page numbers of locations in guide books, such as those published by Lonely Planet and Rough Guide.