A lot of people use their blogs to do book reviewing. Ecto has a really cool feature that lets it integrate with Amazon directly and use the amazon data and a template to start a book review blog. Something like specifying an ISBN and having BlogDesk find the name of the book, author, book image, etc and pull that back into a template would be a great feature. Amazon supports Web Services to get this data so it should be doable.
Thanks for a great editor!