All you RSS readers out there fail to do one important thing–track the history of a given post and keep it hidden after first-view unless the content *significantly* changes. Even then, I only want to see what’s new. So how hard is this? Probably not that hard¹. Bloglines, get on this before I get bored enough to write your competitor…

1) Using a simple vector-space model, you can compute the relative similarity of the root document to each document in the RSS update chain without any difficulty…