What a nifty idea! if you want creative envelopes, go to Maps, map the route from your letter to the other person's mailbox. Print them up, fold them into 8 by 11 envelopes (or smaller if you are sending cards). This would be cool for pen pals
Create gift bags from old book pages. Stamp a bird design on an old book page which has been cut 1 to 2 inches shorter than a second page. Sew or glue edges together. Secure with a brad or decorative button and small Velcro dots.
Great Idea as a Wedding Favor or an Anniversary Party Favor! Give Your or You & Your Spouse's Favorite Book as Favors. Wrap in Brown Paper and add Library Card (templates) for the Gift Tags! Can be given as a Great Gift too!