Yes, this time it is April's hard drive in her 12" PowerBook. Suddenly took a turn for the worse and started grinding instead of spinning. It's a Toshiba 40 GB drive and will be replaced under the Apple extended care warranty that April insisted on having. But the last back up was several weeks ago and even then restoring data to a new drive isn't that straightforward.
To try to make things easier, I purchased Data Rescue II and attempted to recover as much data as I could. This software is "non-invasive" but the drive was fast disintegrating so I got just a few files before the message started to look like this (on about the fifth attempt):
So, the lesson is - back up more regularly and find a way to back up a clone of the hard drive rather than just the user files.