OS X Lion: Manage your kids’ computer usage
As a parent, you want your kids to have a safe and happy experience on the computer. Your Mac keeps an eye out even when you can’t. With simple settings in Parental Controls preferences, you can manage, monitor, and control the time your kids spend on the Mac, the sites they visit, and the people they chat with.
Before you can set up parental controls
Create an account for each child who uses your computer, and turn on parental controls for the account.
Limit apps a child can use
Limit Internet access
Limit iChat and Mail contacts
Limit computer usage