SuperDuper is the perfect disk cloner software (for me anyways). The interface is intuitive and it does exactly as it claims.

SuperDuper has saved my skin on one occasion, and using it to create backup drives has provided me peace of mind since then. I'd bet competing products probably work as well, but I know with 100% certainty that SuperDuper works. When I had my "incident" I was using the free version, and upgraded to the paid version after. If you are doing regular disk backups you'll want to get the paid version as the "smart update" copy (which only updates changes on the disk) is exponentially faster.

I also love how SuperDuper will mount your backup drive, backup to it, and unmount it. For the longest time I had no idea that SuperDuper was capable of this feat. Currently I just leave my backup drives unmounted and let SuperDuper do its thing every night as 2 AM.

If anyone is interested, I wrote a short tutorial on how to mount truecrypt volumes on startup here: http://www.myiphoneadventure.com/os-x/truecrypt-automator-automatically-mounted-encrypted-drives-in-os-x

It's pretty easy to do with automator and makes truecrypt a little less unwieldy.