After searching all evening I finally came across a plugin called "Facebook Comment Importer" (http://wordpress.org/extend/plugins/facebook-comments-importer/), which claims to do just what I need. However, after activating this plugin I received the error message "Warning: Cannot find a post linked to this blog on the last 10 posts of the Facebook wall. Check that at least one of the last 10 posts on your wall links to a post of your blog."
I use NetworkedBlogs on my FB Fan Page, and I'm guessing that this plugin doesn't play well with NB. Am I wrong? I assume that the problem is that NB changes the URLs to all my blog posts to a URL with their web address in it, instead of my own. Is there a workaround for this? If so, please share it! If not, is there another known plugin that I can use that is NB friendly?
Thanks in advance!