I like TimeMachine, no really, I do. I think it is a good idea that has been poorly implemented. Hey, it is Apple, don’t expect it to be right on the first version. 10.5.2 is going to fix one issue, it will provide the ability to back up to disks attached to the Airport Extreme. If you want to do that right now see here.
Another issue I have with TimeMachine is the frequency of backups, every hour is just too much. Every hour my Mac slows down as it starts copying to one of my USB disks. I’d like the interval to be much longer but Apple didn’t provide an easy way to do this. You can now though, even if you are afraid to use the Terminal.
If you are not afraid of the Terminal use:
sudo defaults write /System/Library/LaunchDaemons/com.apple.backupd-auto StartInterval -int 7200
3600 is the normal default of one hour, changing it to 28800 is one backup every 8 hours.
If you want to avoid the Terminal use the GUI provided by TimeMachine Editor.