Mac OS X 10.6: About the General pane of Security preferences
You can increase the security of all the accounts on your computer by selecting the appropriate settings from the General pane of the Security preferences.
Require password... after sleep or screen saver begins: Select “Require password...” to ensure that the computer is safe when left in an idle state. Upon waking, a user account password must be entered before the computer can be used. You can select the amount of time after screen saver or sleep begins before a password is required.
Disable automatic login: Select “Disable automatic login” to require the user to authenticate with a password on log in before the computer can be used.
Require a password to unlock each System Preferences pane: Select “Require q password to unlock each System Preferences pane” to make a user authenticate for each secure preferences pane before making changes to settings. Normally a single authentication is required to change all of the preference panes.
Log out after...minutes of inactivity: Select “Log out after...minutes of inactivity” to automatically log the user out of the account after the computer is idle for the given number of minutes.
Use secure virtual memory: Select “Use secure virtual memory” to encrypt any information from random-access memory written to the hard disk by virtual memory.
Disable Location Services: Select Disable Location Services to stop providing information on the computer’s location to applications.
To delete location information currently used by applications, click Reset Warnings.
Disable remote control infrared receiver: Select “Disable remote control infrared receiver” to stop your computer from being able to receive commands from an infrared remote control.
Pair: To configure your computer to respond to an infrared remote control, click Pair, and then follow the instructions displayed.