I agree. It would be very useful to conveniently have HN, reddit, etc comments already there when I visit the site. Then I could comment on those. On the other

I agree. It would be very useful to conveniently have HN, reddit, etc comments already there when I visit the site. Then I could comment on those. On the other hand it should automatically submit the link to my preferred site, e.g. HN, and post my comment, thus creating a new source for comments. Maybe something like this already exists?