Also, for anybody who has digital photos that have any kind of meaning/value to you, I might recommend Google's online Picasa. It's only $5 a year for 20GB of storage, so even if you aren't willing to pay a monthly fee for another off-site backup solution, $5 is nothing to have some security for your most important photos. I have a Picasca exporting plug-in for iPhoto which is super easy to use, and getting the original versions back off of web Picasa is also very simple.

Even if you have decent back-up in your home, something can always happen (fire, theft, flood, etc.) to render all of them useless.