This was actually one of the uses we'd envisioned for Grazr as a tool, organizing e-books (or more specifically blooks) like this. It's great to see that happen!
There is a lot of power lying in the simplicity that is Grazr and the underlying data format we use, OPML (created by Dave Winer). I sometimes have trouble telling people just what it is we're doing, either oversimplifying the story or talking about our grand expansive vision (usually resulting in that glazed far-away stare) :). It's gratifying when small pieces of the vision start appearing.
Update: Should have embedded a grazr showing it, here you go.