I stumbled over the Taschen bookshop in London today and bought this book.

Menu Design in America

The book is a thing of absolute beauty and the pictures in Amazon don't do it justice. As the title suggests the book is about food menus (as opposed to the computer ones) from the States and who knew how much artistry went into making many of them. The next time you are in a big bookshop, see if they have it and leaf though it. It's an incredible source of design inspiration with colour schemes that almost certainly can be re-purposed for mapping.