We have seen it a million times, the standard comment stream below the blog post / article. But there are alternative options out there. I'm thinking soundcloud https://soundcloud.com/quantic/out-from-the-cellar-5 as a starting point where comments are tagged along the songs timeline.
If I have a long blog post or news article with many different points of interest / discussion it would be useful to a user and author to be able to start multiple comment streams around one piece of content in a more organised way other than a list of what could be unrelated posts chronologically or most replied. I was wondering if using something similar to soundclouds timeline based commenting system but for copy based posts is a sensible idea.