Carbonite Online Backup
I’ve recently converted to Carbonite Online Backup as our "emergency" backup solution for our home PCs. So far, I love this service. Its a flat-rate "set-it and forget-it" off-site back-up solution if you have an always-on internet connection. It automatically backs-up any new files that are added to your computer during periods of low or no internet usage to an off-site facility. The only down-side is that the service may take a week or more to perform the initial backup if you have large, full drives (as I do). After that, it works invisibly by only sending changes to the service. Download new photos to your PC, and they get backed up later that night without having to remember to trigger a back-up, etc.
Off-site backup is particularly important if you use your computer to store valuable digital photos that would be irreplaceable in the event of a fire (that destroys all of your on-site backups).