On the other hand, if it has been ages since you have flushed your caches, or if your computer is running slowly, or if you are experiencing odd problems, it might be a good idea to flush them. However, over time a cache speeds up your computer (assuming that you do some things repetitively), so if you aren't experiencing any problems, you may want to leave your caches alone.

So it is a good idea to occasionally also use a utility that trashes the system caches, and occasionally your Internet browser caches.

Even though running the routine maintenance scripts clears out some temporary files, none of the system caches are touched by them.

Mac OS X incorporates a subsystem based on a UNIX-style operating system that uses permissions in the file system

Repair Permissions: Most users of Mac OS X have not intentionally modified privileges and simply need a utility to reset system privileges to their correct default values.

You should verify your preferences whenever your applications unexpectly quit or something crashes.

Verify Preference Files: Sometimes Preferences Files (.plist) become corrupt.

With 10.4 or 10.5 your prebindings are updated every time you run an Apple Installer.

Update Prebindings: Prebindings allow applications to launch faster.

In that case, you may want or need to run these manually. If your computer is shut down or in sleep at the designated times, the maintenance does not occur.

Periodic Routine Scripts: Mac OS X performs background maintenance tasks at certain times if the computer is not in sleep mode.

IceClean is a powerful System Maintenance and Optimization Tool using only UNIX built-in System Tasks to help your Mac stay healty and to keep it running smoothly.

Ice cleaner mac