Indestructible books for babies? Brilliant. Whoever invented board books is a genius. Some of the best board books my babies ever heard (or chewed on) are by Sandra Boynton. We discovered her through one of her non-board offerings,
after that hippo party we were hooked. Her books are simple and engaging, and very, very clever. I read The Going To Bed Book every night for years, long after my kids stopped chewing on it.