While not bootable, I have to mention the online backup alternative. There are many services that offer backups in the “cloud." In other words, you upload your data to their servers for backing up and when you need it you can download it. I currently use CrashPlan as my service of choice. They offer unlimited storage at a great price.
The benefit? If your hard drive backups are destroyed you have your stuff backed up off site for retrieval from anywhere.
The downside? These services come with a monthly fee. It also takes a REALLY long time for the initial backup. I have been researching this for myself and have not jumped in. Most monthly fees are only $5, which is not bad.
However, I have tried uploading to several services and I am afraid I am going to exceed my Internet provider limits. One service I tried got stuck after 500mb. For now I am sticking with external drives. Also, not all services can backup data from an external drive (which is where I store all of my photos and movies).
So now you have several backup options in addition to Apple’s Time Machine. I actually have a Time Machine backup in addition to my DejaVu backups. Whatever option you choose, make sure you choose one. Backing up is critical. You don’t want to be the one that looses all of those personal files because you didn’t have a backup.
Ideas? Post your backup solutions below.