Dan, you know what would be cool for HN comments? The ability for each node of a thread to be annotated with topic names. For example, if the node close to the root node here were to be labelled "Israeli politics", I, a user interested in the technical aspects of the topic, can immediately avoid it. This feature will be a killer feature for all topics that have divergent sub-threads! (I haven't thought further than just the annotation by end user feature - so, whether it ought to be at user level or a global one ... I don't know). :-D