More ideas for book social software

danah boyd wants to like Books We Like, an online service for collective discounts and recommendations in book purchasing.
In the comments, Brad deGraf writes about supporting the import of an existing book spreadsheet, and a future feature that will import Amazon wishlists.
Even nicer would be something that combined an Amazon purchase list, with the “I’ve read that” responses to Amazon’s recommendations (which catch books you’ve read but not bought on Amazon).
For this to work, Amazon would need to componentize its records of the books its customers have purchased (from them or elswhere). Then Amazon, or somebody else, would enable the user to create a public view that could weed out gift books (Audobon Quarterly, for the birdwatching uncle), and purchases one might rather not advertise.
Or perhaps, if more purchases are done through Books We Like, their database will become the master for more of us, rather than Amazon’s.
Because BWL is an infomediary, they would have more of an interest than Amazon in providing tools for individuals to manage and combine their book databases. Amazon offers APIs but has a conflict — they have less of an interest in letting customers control their own data.