Sometimes I just want to lock my mac and run a software in background, for example to stream audio. For this kind of things, you can’t use the clasic sleep mode. You need something else. How can you lock your screen like in Windows? In OS X, if you look in the  menu, there are only Sleep or Log out.

So, here is how to lock your screen: CTRL + SHIFT + POWER. Yes, really simple! You just need to activate Require password immediately after sleep or screen saver begins in the security panel of OS X.