Portland, OR based Engrave Your Book use natural methods to create these beautifully designed book covers. They'll fit your handy Moleskin notebook like a glove and turn a few heads as you jot down your deepest thoughts.
I like a lot of the designs that are available in the artist series, and there are MANY to choose from. If you are so inclined, you are encouraged to submit your work for a chance at becoming one of their featured artists. I was also really impressed with the custom orders that they feature on their site. Apparently everything looks good engraved in leather!