[Raven]

I live by my backups. I have two externals on my desk, both 500gb myBooks, one of which handles Time Machine backups and all files that I don't want on the laptop's internal drive. The other one (which you almost can't see in that picture, as it's black and stuck right next to the silver one) is an external music library that's shared over the network.
I have important files (my thesis and data, heh) backed up on, at last count, six physical drives and two externally-managed servers (a friend's, and Amazon S3). There will be no 'dog ate my homework' for me!

@Yuiichi - You should look into the myBooks re: big loud and ugly. Even with two, they're whisper-quiet, conveniently stackable, and I at least think they're not bad looking. Not to shill 'em or anything, but I'm so much happier with them than any previous externals I've used that it's not even funny.