Back when facebook apps first started I wanted to write an app that allowed a user enter in all their books and allow a library like checkout system where your

Back when facebook apps first started I wanted to write an app that allowed a user enter in all their books and allow a library like checkout system where your pool of possible books to checkout were the collection of all your friends books (where they allow "friends to checkout" on certain books). If you continue with this, I would love to see a similar feature.