One phenomenon seen in blogging is that when someone posts something that resonates with lots of people, lots of people link to it from their blogs, and if the original blog allows trackback pings, lots of trackbacks show up in the comments. While this does bring more attention to the original entry and to the idea in general, it's not a perfect method. For one thing, it make the comments in the original blog more cumbersome to read because you have to wade through all the trackbacks that are nothing more than copies of part of what you've already read. Also, seeing the meme requires parsing the links out of the blog entries that link back to it. Here are a few ideas for purifying the process.
First is the idea of reference entries. They contain no content, only a link to the entry in the original blog. The referenced entry is loaded automatically by the feed reader, and perhaps even included in the blog's website automatically by the blogging software (that information could be cached for performance). Referenced entries should be displayed in some distinct manner to indicate that they are coming from elsewhere. This type of entry would make it supremely easy for aggregators to track how popular a particular entry was with other blogs (or more accurately with other feeds) because all they'd have to do is count the reference entries pointing to it, which would be trivial to do.
Second, blogging software that supports trackback should display trackbacks separately from other comments. Best would be to have trackback updated to incorporate the concept of reference entries so that it could simply list reference trackbacks, and then maybe it could continue to display (possibly in a different place of distinct style) other trackbacks which may include some additional commentary.
This issue has been in and out of my mind now and then for a while, but this particular idea just came to mind today. Perhaps I'll write more about it later after the idea has had a chance to grow and become better formed.