Thinking about a cover design

While Rafael and I have had a few conversations about potential cover designs for the book, we're also curious what you think. Once we hit on the "field guide" theme, it seemed like it might be a good idea to incorporate some kind of old-timey field guide-type look and feel into the cover design, if not the book itself. So I've been wondering what they might look like.

(Keep in mind that I'd like this style to work across multiple books in a series. This isn't just for this one book, though the specifics of whatever photo or illustration appears may be.)

If you do a Google image search for "field guide," you can see some inspirations. In fact, the "vintage" option at the top is particularly interesting.


I've also been looking through stock photography. The following examples are from iStockPhoto, and obviously if we go with one of these designs, we'd pay for a commercial license to use it.


The other thing I keep thinking about is that connection to a travel book series. I've cited Rick Steves' guide books before, and the great identity and brand that they convey. Perhaps there is some inspiration there as well. 


Anyway. We'll play around with some ideas, but we're very curious what you think.