Kindle gets library book lending

This does seem to be something that needs to be broadly considered when it comes to new technology. For example, Netflix - one account for my household, but there's no separation between recommendations for my wife, my son, myself (which makes for some amusing confusion). In general, the possibility of personalization needs to be considered for applications where you want single-billing but might have many individuals within that account.

I know quite a few families in this situation that just re-register kindles between Amazon accounts when they want to grab a different book. According to them, registering a device switches its account, but does not delete or remove stuff you already have on it.

You can have multiple devices registered to the same Kindle account. My wife and I use the same Amazon login to buy everything (yay, Amazon Prime), including Kindle books. That means her iPad and my Kindle both get to download and read the same books. No lending necessary.

I believe you can lend, to friends or family or whomever, if the publisher allows, and for whatever time frame the publisher permits (I've only seen two weeks as the limit, but the wording is such that it may vary). The inconvenience is that if you lend a book to someone else, you lose the ability to read it until you get it back.