The HD in my 12" PowerBook bit the big one a few weeks ago. Luckily, I was very smart and backed up everything onto an external drive a few days before it croaked. The funny thing about this whole situation was that I did this back-up in preparation to replace the HD.
Although I had been warned by other people, I was not aware of the true pain that awaited me: installing the new HD in the PowerBook. I would like to send a very warm "Screw you Apple!" for making it almost impossible to remove the three screws under the battery compartment. It's the same emotion that I have for the *brilliant* minds that came up with the injury-prone plastic packaging.
After much pain (and also two and a half hours), the HD is in place. Now begins the fun process of OS install. I pray I never have to go through the computer equivalent of a root canal again.