Thanks so much! My concern with uploading images has to do with unnecessary duplication online as well as local storage: I usually link out to Flickr for personal photos or CC-licensed images, and try to minimize local image storage on WordPress. I’d rather not fill the media library with book covers when reviews are just a small part of my site. However… I also don’t want to use others’ bandwidth with hotlinking, as you say. I’d love to find an ethical way to link and pull in cover images.
It may be that there’s not an ideal option for integrating with OL, but I’ll look forward to seeing what you find.
