I've found it! Somebody to tell me when my library books are due or when a hold is ready for pick-up. It's Library Elf, and I'm tickled pink to find it! This little Elf will send you an e-mail and/or RSS feed (on Bloglines or similar) to let you know when your books are due. Registration is free, and then you can find your library and add your library card (and your children's) to your account. I was pleasantly surprised to find my library on the list; I was afraid that Canadian libraries would not be included. So I took about 3 minutes to register and add my card, and now I will never have an overdue book again - hopefully! Here lately I've had a rash of overdue books, and this was just what I needed to help out. Wes was impressed!
Thanks to Mrs. Happy Housewife for the information!