A "repost this story to my blog" button.
Huffpo has a similar feature that I use all the time. For theirs your comment to the story gets reposted with some of the story.
When the button is clicked, a window would pop up for you to write an intro to the post in your own words. It would give you the choice of which of the standard blog types you use. When you select one, it opens a form for you to add your blog url and login info.
When you click "Submit", it would post your intro at the top, and the first few paragraphs of the story, or what's above the orange fleuron of justice.