I&#x27;m not super interested in the thoughts of those I &quot;know and trust&quot; as I&#x27;m reading (since a circle of real friends would be too small and too unlikely to have all read the same things for this to be effective, I&#x27;m assuming this is the social-network definition of &quot;know and trust&quot;, which is to say &quot;follow on Twitter&quot;, so that&#x27;s an <i>even stronger</i> no) <i>but</i> high-quality, extensive commentary and annotation by multiple experts would be great. Many books have some of this in the form of an introduction and some footnotes&#x2F;endnotes, but I&#x27;d love the ability to turn on much higher levels of this for, say, second readings.<p>Unfortunately it doesn&#x27;t seem like ebooks are good at handling even <i>basic</i> annotations—certainly no better than dead-tree books—so I&#x27;m not seeing that happening any time soon. Plus if it ever happens it&#x27;ll probably be some stupid online service, which I don&#x27;t want. I want it to be part of the book, like DVD commentary tracks, or at least a downloadable add-on file of some kind that sticks around as long as I want it and can be backed up.