Atama Sesame 2, Locks your Mac when you walk away.
Sesame is the easiest way to automatically lock your screen when you move away from your Mac. Carry Sesame with you, and when you walk out of range of your computer, it will lock your screen. You don’t have to remember to put your Mac to sleep or use hot corners, Sesame takes care of it all. Your private information, e-mails, spreadsheets, Facebook and Twitter accounts will be safer simply by carrying Sesame on you. When you come back, Sesame will automatically unlock your screen, ready for you to continue your work. It’s that simple.