There's really no excuse for not using Time Machine on Mac. I think it's one-click setup (a yes/no dialog comes up the first time you plug in an external hdd to a fresh installation, if memory serves).
If you are afraid you won't be plugging an external hdd in enough, I think it's worth getting a Time Capsule (automatic Time Machine backup over wifi).
If you are afraid you won't be plugging an external hdd in enough, I think it's worth getting a Time Capsule (automatic Time Machine backup over wifi).