BorneoBound's strategy is exactly what I used to do... until I found that Retrospect does NOT work in Tiger.
Here's a posting of mine from another thread:
I "had" been a Retrospect user for at least 10 years... until last week.
Since upgrading to Tiger, and then paying for the upgrade to Retrospect 6, I have been unable to complete a backup. I backup to a separate FW drive.
I consistently got full out crashes some part of the way into a "Duplicate." (I duplicate the entire drive to a folder on the backup.) I tried all manner of suggestions from the Dantz website: have no other drives attached, have no other apps running, only duplicate docs, it must be bad memory, Apple screwed up with FW, etc.
Of course, I'd already used my ONE tech support incident with Dantz... and it would be $70 to even talk to them about what clearly seemed their problem.
Also, there were reports that the Retrospect AutoRun files were causing people's machines to slow down. I'd definitely been having slowdown problems and recently removed the Retrospect files... no problems/slowdowns since... though I wouldn't be able to swear that Retrospect was causing the problems at this point.
All that said... I tried SuperDuper. What a gem! Gee... it was able to copy over 110 GB of data to my firewire drive... without blaming Apple, Memory or making me go through a gauntlett of "try this or thats."
SuperDuper only costs $19.95... and when I had a tech problem I got a response back right away. (My bad... I should read ALL the instructions... avoid skimming.)
BTW... you don't have to use the entire disk for a backup... or even a partition. You can create a Disk Image on the backup drive... and SuperDuper will backup to that image. Instructions on their website.