I don't understand why people won't use Time Machine. The big advantgage with Time Machine vs. a regularly scheduled backup, even one that occurs twice a day, is that you are never more than an hour away from all the files you're supposed to have.
Recently, my MacBook Pro's 120 gig internal drive died. Time machine had a backup that was twenty minutes old. After I replaced the drive, I booted the MacBook Pro with the Leopard DVD and did a full restore. Bingo: evertything back the way it was 20 minutes before the drive died. If I did weekly backups, I could have lost quite q bit of data.
But, in all fairness, this is the first time I had a catastrophic hard disk failure on the Mac. What happens far more frequently is that I realize that the file I trashed a couple of hours ago was the wrong one, or I edited a file and inadvertently deleted something from it. None of this is a problem with Time Machine because it just does its thing and you don't have to worry about it.
Before Time Machine, I used Retrospect, and I still like the program. You can make backups (compressed) or bootable copies of volumes, you can script what gets backed up and when, and if you're on a network you can back up workstations from a server. I still use retrospect occasionally to copy a volume (for instance, when I want to replace a hard disk); it's fast, safe, and reliable.
But Time Machine, I feel, is brilliant. I fail to see to what extent SUperDuper provides better protection against data loss.
Daniel