Using an online backup service has saved my system 2 times now — it's an essential part of my home and small business management process.
Have bucketloads of photos or videos? We do. With 2 kids, 4 dogs, 3 horses, and a boat we're always on the go. That means loads of vidoes and pictures (my wife's tool of choice here is a Nikon D70 digital).
To our horror (though it eventually happens to everyone) we've lost our hard drive 2 times, with a 3rd 'close call' that we narrowly avoided.
Fortunately, we used an online backup service that saved our bacon (especially mine, since she relies on me to get this stuff done right…)
It's fully automated, and depending on what service you use it is essentially limitless as far as storage capacity.
About the only thing I struggle with has nothing to do with the service, it has to do with the max of 2gb DSL service we use for our internet connectivity living out in the country. Not a huge deal though, I just schedule the backups to run in the middle of the night.
So save yourself some sanity, and possibly even your marriage. Sign up and "forget about it…"