Library Elf is a free service that will email you when a reserve has come in, or if any items are overdue or – and this is especially handy! – a few days before something is due, so that you may return it before we start charging our reasonable overdue fees. There is a demo here. All you need to do is to sign up; it requires your library card number and surname to access the library’s database and your email address to mail out reminders.

Be aware, however, that it’s not connected to Wellington City Libraries (it is based in Canada), and you ought to check their privacy policy first.