In particular, I liked Knowledge Workers Don't Know How to do Knowledge Work due to information overload, Knowledge is Best Transferred by Conversations and we need to respect that, Everyone Learns, Organizes and Processes Information Differently - and so integration among various tools is important, Management Doesn't Want or Need KM Decision Support because they are hired for their expertise and decision making - for which they don't depend on other knowledge, and most important - Stories are Critical to Knowledge Transfer - eventually it is storytelling that is most effective.
The architecture will need a central server: You report mouse location (within the DOM!) to this server and your peer will listen on these events. Ideally this should be part of blog server itself and a simple mechanism to allow your peers to subscribe to your events.
This also leads to extension of blog concept to a generalization of protocol for exchanging "What I am doing now" - in real time. For example the sites I am visiting just now, or research I am doing. The interested folks from the community can join together and produce a common blog as a result. (Such an interaction often tends to be more productive.)
Perhaps someone already has this implementation!