Better yet, open "Keychain Access", go to the preferences general tab, and click "Show keychain status in menu bar". Voilà, now you can lock and unlock keychains without switching applications. (This has been around for a long time, too.)
Don't forget, unlike windows, LOCKING a mac is not easy. The only way I know is to use the lock command of Alfred. In windows: Windows + L = lock boom. Because of this, most people in the office leave their macs unsecured.
