I had a backup 500GB drive die on me today -- the thing doesn't even spin up when power is applied. ARGH. It sucks to have a drive die 3 hours before an international trip. I'm backing up that volume over the network now. I've griped endlessly in the past about the poor network performance of Mac backup apps. While I can get 30+ MB/s over gigabit when copying a file over the network, I've been unable to get more than 4-6MB/s while using a backup app, and believe me -- I've tried quite a few. At 6MB/s, the backup will take 23 hours. Yippee.
So be sure to back up regularly, readers. Drives die all the time, and it's just a matter of time before yours does!