You don’t really understand the importance of backups until your hard drive crashes. With most backups, you’ll need to reinstall the operating system and then restore all of your data. OS X comes with a handy tool that will let you create a live copy of your hard drive that can be started up and run just like it is your computer. While we're on the subject of backup, you might be interested in taking a look at an older article here on Non Stop Mac that discusses secure backup and storage using a disk image and an iPod.