"When you have one book for people to sign," says Gartin, "a long line forms, causing a bottleneck at the entrance. But if you provide a stack of wish cards, 10 people can write at once." Plus, the messages can become a decorative element if guests pin heart-shaped notes on a clothesline at the reception. You could also ask friends and family to deposit their cards in an old-fashioned mailbox or a keepsake container, where you can store them forever.