Annotea + OPML + FOAF
Danny Ayers has keyed in to the potential intersection between blogs and annotation services. The idea of having related blog entries available passively while browsing is a fantastic one. This is one of those awesome ?semantic web? ideas that would be relatively trivial to implement, along the same lines as the FOAF+de.licio.us idea. Part of the power of both ideas is the realization that much metadata is implicit in our day-to-day activities and need not be maintained manually.
One of the more powerful ideas is that of implicit ?social networks?, in this case based on blog subscriptions, linkage, and so on. This is one of the concepts that Steve Gillmor has been pushing for awhile; note how he evangelizes to Google’s Sergey Brin in this interview.