Mozy.com
I've recently started using Mozy.com for on-line backups - it's pretty neat. The background operation allows it to have very current and very granular backups. I don't really trust their encryption though, so I'm using my normal backup program to a folder, with incremental backup on and fully encrypted and synchronizing THAT folder. It works, although it is very inefficient compared to normal operation, of course... For less important stuff I use the built-in (LOCAL!) encryption. The price seems pretty good if you use the free or personal version, too.