If you don't have the time to run out and buy your own external hard drive (or the patience to figure out how to format it) you can keep it simple sister, and back up your docs and data with Mozy. You probably have a ton of stuff floating around on your computer that would be a heartbreak to lose, and a back-breaker to retrieve. In other words, it's not cheap.
With Mozy, you don't have to worry about all that cause you can back up your data in a super-secure online storage system that is free up to 2GB, and only $5 a month for unlimited storage. Did you catch that? Unlimited. And when I say secure, I mean banks, high-profile companies, and even a few Hollywood studios use it to back up their important data. Live off of your laptop? Do yourself a favor and leave the external drive at home and back it up online.