Just boosting this request again. I can't update all the books I have read manually and I wasn't using a book tracker before now so scanning the barcode would be the easiest way to do this

This can be a can of worms, and anti-useful if not done properly. When you start looking into this, please consider the following use cases:

• At a bookstore or library or friend's house, I want to see: do I have this book on any of my lists already? (Including owned or read). Have my friends reviewed it? Also make it easy to see book summary and top reviews. I will probably want to do this WITHOUT adding the book to any shelves, i.e. just browsing.
• At home, I may want a quick way to update shelves: owned, want-to-read, read, (some day) loaned out.
• At home, some catalog-minded people might want a batch way to say "I am scanning bookshelf X in room Y" and have all subsequent scans auto-go to that shelf.

Am really impressed with your site and development model so far (one day in). Thank you!

Once we get to the point where we have a mobile app, I definitely want us to look into this one.