I just recently found this page here on WikiTree while helping a new member and I think it's pretty great! Thank you Therese Schmidt for starting it. :)
I've already sent an email with several books to be added that I have and can do look ups in.
Genealogy Resource Exchange
Do you have any books that are rare and hard to find that you could do look ups in?
There is also this page Books Owned by People on WikiTree