Backing up your iTunes library or purchases!
Hard drives fail often enough that you cannot rely on them to keep your files safe. You must always have a backup (two backups is better). You really don't need Apple's Backup application that is exclusive to .Mac users just to backup your iTunes library or your iTunes purchases. If you ripped all your CDs and threw them away, you wouldn't want to lose all your music, or if you still have a backup on CD, you can choose to backup only iTunes purchases. This great feature is actually built into iTunes. It is called "Back Up to Disc". The features it lack is the possibility of backing up on an external hard drive and the possibility of backing up following a schedule. You can access this great feature in iTunes' File menu.