I've actually thought of this type of thing. I read a lot, and it would be nice to have some sort of extrinsic motivation to nudge me to type up short summaries of the books I read. I don't think I am a particularly skilled writer, but I don't think it would be too hard to create some first drafts of summaries of 5-10 EA relevant books, and then other people could add in their own edits over time.

Here is a (very simple) start. Think of this as a minimum viable product.

I might be up for doing something like this! I might DM you about it.

A few follow up thoughts

• This wouldn't really have to be it's own project/website/organization, right? It could just be a tag on the forum for book review or book summary. Right now I think it isn't really culturally normal for people to put book reviews/summaries of EA-related books on the EA forum. To be that feels a bit too much like a personal blog. But cultural norms/practices can change, and I think it would be acceptable to have book reviews/summaries as long as A) the intent is to help other people and B) the content is EA-relevant.
• Are you thinking specifically of having 5-20 minutes of audio providing a high abridged version of the book, or do you think that written text summarizing the book would be fine?
• Regarding the on demand aspect, sometimes before I read a book or after I read a book I Google around for summaries. Usually I am able to find at least a few people's writings, although if the book is quite obscure I might not be able to. So it seems that with a relatively small amount of effort we can already access summaries of most books.

1) Which books? There should be easily a 100 books related to EA (more and less broadly).

2) Some of the books are thought stimulating (the value is readers' contemplation about unanswered questions), some informative (present valuable info that is useful to problem solving), some directly motivational (get readers focus on an important problem), and some vaguely motivational (inspire people to do good by discussing other topics).

I think summaries could be counterproductive for vaguely motivational books but could be also improving otherwise readers' experience , because if one enjoys reading and realizing that they can do good, they can feel better or worse about it than if they skip this step and go straight into reviewing an option of doing good effectively.

For directly motivational books, summaries should be the most valuable (people should be informed about important issues) but the summaries should be published only after various pressing issues are covered (for example, if only wild animal welfare books are summarized then people who do not want to read the entire text could focus on this area and make it so that AI safety has attention disproportionate to the marginal value/need).

Thought stimulating books could be actually discussed without (everyone) reading because that diversifies perspectives.

Summarizing info that helps solve problems can be valuable to anyone who is resolving the issues.

option of doing this on demand.

I think EA orgs would enjoy it if that helps them in what they do. Some people may be interested in having different people read books and then summarize evidence and reasoning on some questions. Then, one person/org can benefit from knowledge and thinking of multiple people and be thus more efficient.

I would be interested in writing summaries of books. I did this with two books that I read within the past two years,  The Human Use of Human Beings and  Beyond Good and Evil. I imagine that I might have excluded many things that I expected myself to easily remember as following logically or being associated with what I did write down. For The Human Use of Human Beings, I tried to combine several of the ideas into one picture. I think what I had in mind was to put all the ideas of the book into a visual dashboard (I did not complete such a visual dashboard).  I don't think I still have the summary that I did of Beyond Good and Evil , but I imagine that for that one it is possible I wrote down many passages which I did not completely follow. 

Writing a summary of a book can help to process the book more and in different ways.