The Kindle reading network has some interesting possibilities.

• Book clubs
• Education: 
  • K-12,
  • College
  • University
  • Community Ed.
• …

The key might be to arrange around some circle of relevance. Classes and topics make sense as these are areas one can identify interest in. How do you find areas of interest that are below the surface of consciousness? Perhaps this is solved by connecting with people from other networks something like a cross-pollination of interests.