This application should definitely be free because Panther has this feature already built in. I never log out, and I simply lock my screen when I walk away from my Macs. Go to System Preferences>Security, and then tick 'require password to wake this computer from sleep or screensaver,' and then either put your Mac to sleep, timed sleep or launch the screen saver, and the screen will be locked when you get back I have also found that it works better than LockOut with other apps left on when I walk away, while LockOut has crashed forcing a restart to get back in...no thanks.