Time Machine built into Mac OS X since Leopard (10.5) is an all around good backup of your system and data. It’s only shortfall is that it backsups to a connected or internal drive. If that drive should fail, theft, fire, or other natural catastrophe then you’re out of luck. My solution is to use two Time Machine backup drives. One attached, one safe and swap them on a monthly basis. I put the detached disk in a fire safe box just in case. This is a pretty good method, in the worst case you’d only loose at most 1 months of data.
On a monthly basis I have an iCal reminder set to remind me to swap. Simply eject your time machine drive and disconnect it. Then reattach your other drive. Open Time Machine prefs and point it to the newly attached backup drive. It will pickup where it left off.
I found this blog article with more in depth info and process on the matter. It’s good to see others are using the same strategy.