Library Elf

No, as much as I wish I had, I did not invent that name.  Library Elf is a service that helps you keep track of your library materials to avoid those overdue fines.  The free (basic) service allows you to track one library card and will give you overdue email alerts for that one account.  With the premium service ($20 per year) you can track multiple library accounts and can customize, including getting text alerts and have iCal integration.

Hat tip to ProfHacker

Ernster, the Virtual Library Cat