With increasing down and upload speeds, online storage and backup is becoming a viable option.
I have an automatic backup system that copies a full disk image every week to an external drive. But I would still be in trouble if there was a fire, or my gear was stolen, or (and I have seen this happen) internal and external hard disks were both damaged by a power surge.
Mozy offers 2GB of secure remote storage free to home users, or unlimited storage for $4.95 per month.
You really need cable internet or ADSL2 to make this practical for most users. But if you do, it is worth thinking about.
Disclaimer: I do get a (very small) commission (like $1) if you click on the link above and sign up for a plan. So I hope you will. But mainly I just thought it was interesting.