My mom is planning a shower for me in August and has been asking about details (food, registry, etc.). Being book lover, I was thinking about requesting that everyone bring a book instead of including a greeting card. Doesn't have to be an expensive hardback picture book or anything, we just want to build a library for our baby and thought this might be a great idea. If they want to include a thoughtful note in the book itself, that would be lovely, or just a handwritten note that I could paste into the book or add to a scrapbook.
Is this reasonable? Have you ever done anything like this or attended a shower where this was requested? What do you all think?
I don't remember seeing this in any of the previous posts (please correct me if I'm wrong!), so I thought I would ask. 
Re: Baby Shower - Books instead of cards?
I love it though- it was fun picking out a book that wasn't as common as something like Goodnight Moon, but also finding one of my favorite books as a little girl for her baby to have. Plus, children's books are so dang cute. I have a hard time stopping myself from picking them up at the store!
It wouldn't let me attach it, but here is the poem I plan on using if my hosts agree with the idea!
You can write a personal message in a book, keep it for years and USE it. You can write a personal message in a card too, and then I'll feel bad about throwing it out and put it in a shoe box for the next 10 years, but never use it...
@mlobrummond, I love it! Would you mind if I sent that poem to my mom to include in the invites?
Bottom line if it is worded as a fun suggestion rather than a requirement it is not demanding. People still can choose whether to participate in it or not. Just know that maybe they will reduce the big gift cost to accommodate the book request.
I found the older women who attended her shower didn't like the idea.
However, I think if you use clever wording like the poem from Pinterest and communicate it like, "we'd LOVE to get books to build LO's library" instead of "you must bring a book in addition to whatever else you're giving us" it works. Perhaps work into the wording something about brining a favorite book from childhood; you may discover some books you haven't thought of that become LO's favorite.
Or you can register for a bunch of books. Any store that sells books, you can add them to your registry, and Amazon has a ton of options.
Just a thought on getting multiple copies of books: babies tear up books. If baby tears up his favorite book and you've gotten two copies, you can just toss the torn up copy in the recycling bin.
Edit: I also included that it could be a well-loved book or a brand new one. I am not opposed to people going to half-price books, goodwill, or regifting a book they already have.