The blog I run uses Daring Fireball style links, i.e. where the post title (and rss feed) links directly to the linked article not to my blog post.

I would love to be able to define the custom field that’s used in the posting to FB, etc where instead of linking back to my post, it links to the original post I’m linking to.

For example, there’s a custom field I used called linked_url. When that has a value, a plug-in I have “DF-Styled Linked List” uses that field for the links and appends a link to my blog post at the end.