I do what I like to call multiple, cascading backups. External HDDs, connected by USB-II are dirt cheap, you own and control them -- not some faraway stranger. My primary B/U drive is a 500 GB unit that's usually in the same briefcase as my computer itself. Obviously, that's a vulnerability in and of itself. On the up-side, if I have a crash on the road, all I need to do is go to any other accessible computer, and plug-in my backup drive, and I'm pretty much in action.
Every couple of days (no less than once a week), I "cascade" the primary backup to a secondary external HDD that I keep at home. Occasionally (not often enough...), I cascade the secondary backup to a tertiary HDD which can usually be found in the trunk of my car or in the desk at my office.
In addition to that, realizing the sensitivity of family photos, I will manually do yet another backup of my photo directories.
Short of a nuke popping off above Pensacola, I think I've pretty well covered the data loss risk.
AS for the online services, I just don't feel comfortable with the idea. I have a certain amount of sensitive data (mostly client information) that I just don't want out there at risk. Why not just buy a pair of external HDDs? You own, possess, and control them. One will eventually die (we hope not at the same time...), and as soon as it goes, you replace, copy over, and then wait for the older one to go. When it does, repeat the process.