It would be nice if comments from e.g. Hacker News were overlaid on the page you were visiting. A browser plugin could show you comments from multiple communit

It would be nice if comments from e.g. Hacker News were overlaid on the page you were visiting. A browser plugin could show you comments from multiple communities. That way you discover the comments even if you find the link another way, and it would be easier to open a bunch of tabs without remembering to open the comments too, etc. People wouldn't need to add comments to pages themselves.