Dan Frakes writes: "For the most part, Mac OS X doesn't need a lot of day to day maintenance -- it crashes less than the "classic" Mac OS, and individual application problems are less likely to affect other applications and the operating system itself, so most users will find that serious file, drive, and directory damage are fairly rare. That being said, don't forget Murphy's law - eventually something will go wrong. When it does, you may as well be prepared, so it's a good idea to have the right tools handy and to polish up on your troubleshooting skills. You can kill a number of these birds with a single stone using the handy utility AppleJack."