OS X Backup


I've had my powerbook for about a month now and am pretty comfortable with it. I don't have many complaints---its just an awesome machine. I'm starting to worry about things like backing up. Thats' my question for today: how do you back up OS X? I've found lots of commercial packages, and I don't mind spending money to get something, but I'd like to know its going to work. My most likely backup scenario is across a network to a SMB mounted drive.