I think the library automation systems that incorparate the use of SMS (short messaging service) are thinking ahead. This is the way to go. At my library we offer our patrons a service called Library Elf, which once they sign up, they are notified of holds and items coming due. These notices can be via email or text message.
I am still getting aquinted with text messaging. I do text my family and few friends but I don't think I will be able to text as fast as my son or be able to text without looking at my phone.