Locking your screen when you’re away from your computer is very important when there are other people around. You don’t want anyone messing around on your computer. In Ubuntu you can lock your screen very easily. Once your screen is locked, it will immediately start the screensaver. When someone tries to use the mouse or keyboard they are prompted for a password. If they don’t have the password, they can’t access your machine. This password is the same one you use to login with. Here’s how to lock your screen…
The quickest and easiest way to do this is to simply hit CTRL+ALT+L. This will automatically lock your screen, and start the screensaver. If, however, you don’t want to use that keyboard combination, there are other ways to do this. In this case, you’ll need to bring up this box, and choose the Lock Screen option.
You can bring this box up a few different ways. You can also hit CTRL+ALT+DEL, or you can go to the System menu and select Quit, or you can click on the Exit icon on the taskbar. If someone tries to wake your computer up from the screensaver, this is what they’ll see…
If they don’t have your password, they won’t get into your system. They can login as a different user, and this won’t affect what you’re doing. When that other user logs out, the machine will just go back to yourscreensaver. Another nice little feature is the ability for someone to leave you a message when your machine is locked. All they have to do is click the Leave Message box after they wake it from the screensaver. They type their message, hit Save, and leave. When you come back & login, that message is displayed in the lower right hand corner of the screen until you close it. Very cool!
Notice the non-darkened area
Zoomed in view[digg=http://digg.com/linux_unix/How_to_lock_your_screen_in_Ubuntu]
[...] and need to step away for a moment. You can achieve a locked screen, just like when you do it the graphical way, with this [...]