Blue Velvet said:Once in a while, I run MacJanitor. It's free.
Elan0204 said:This is a good recommendation. The UNIX underpinnings of OS X run certain jobs, called cron jobs, daily, weekly, and monthly. They are scheduled to run at 2AM, but if your computer is asleep or shutdown, they will never run. MacJanitor is an easy way to run the jobs yourself, at your convienance. If you don't leave your computer on (and not asleep) 24/7, then running the cron jobs yourself is an important part of keeping your Mac in good health.