I try to be a nut when it comes to backing up my computer and office computers. My office computers are backed up on an NAS device, plus backed up off site on at least one other computer. Our production servers are backed up so often, in so many different ways, you would think I was a nut.
Personally, I use to back up my laptop a few times a week using SuperDuper. SuperDuper does a direct clone of my hard drive, onto an external hard drive. This way, if my hard drive blows up, I can theoretically pop in this other hard drive and get going from my last back up. The thing is, SuperDuper has not yet come out with a Leopard compatible version and it has been stressful to say the least.
So I finally took the plunge and bought a new hard drive so I can run Time Machine on my Leopard OS. Yesterday, I got the drive from Buy.com, a Western Digital My Book Essential 500GB version, and started the backup at about 2pm. It finished the 90GB backup at about 6:30pm. That was my first backup. Now every hour, when this hard drive is connected to my laptop (only when I am in my office), it backs up every hour. It stores hourly back ups for the past 24 hours, daily back ups for the past month and weekly backups until this drive is full. The UI is amazing for restoring lost or old files, simply amazing.
My hope is that when SuperDuper releases a Leopard compatible version, which I am excepting within a week or two, I will run both SuperDuper and Time Machine as backups.
SuperDuper will give me the bootable clone of my hard drive from my last run of that backup. Time Machine will give me the file by file capability to restore files historically. I think I will feel completely at peace once I run my first SuperDuper backup on Leopard.