I read the onine version of a newspaper. Until it was bought by Gannett and changed its software to "Pluck" (feh), it had a great feature.
When you read an article, it had a comments link with a number of comments. It didn't show the comments, though.
You clicked on the link, and it dumped you into the newspaper's discussion forum. If you were the first to make a comment, it automatically started a thread with subject "News: [%%title%%]", that is, the title of the article.
You could also start your own threads on whatever subject you liked.
It worked really well for the paper, which had a thriving online forum. New people were regularly brought in via articles. The switch to Spuck pretty much killed the forum, since people now comment on articles only, and forum discussions are detached from the articles.
Would a plugin be able to do this, maybe working with simplemachines? (phpBB sucks, and I don't know if vBulletin or InVision would allow access to source code, or if it'd even be necessary to use source code . . .)
Ideally, the plugin would show the latest few comments on the article page, then drop you into the thread when you wanted to comment.
Maybe there's something I didn't find in the search?