NOOK has a fancy little feature that allows you to lend some of your books to other NOOK users. The Support and FAQ's on the B&N site notes that not all books are lendable, and you can only lend a book one time to one person, ever.
If you're a NOOK user with a book you're willing to lend, or a NOOK user looking to borrow a specific book, please feel free to post in this thread.
Don't forget to use your manners, and PLEASE, don't be just a borrower! ;)