Now that the Timeline is being rolled out to everyone, there is no official way to remove it
How to do it in the old Profile
Once you have logged in to Facebook, on the top right hand corner of the page, click on your name or small profile picture and then on the “Edit Profile” button that will appear right below.
Once you have done this, in the left sidebar, click on the option that says “Friends and Family.”
Now, at the right extreme of the Friends section, located near the bottom center of the screen, click on the audience icon, the one indicated in the next image, and in the appearing menu select the option “Only Me.”
If you don’t want other people to see your friends list in your Timeline Profile, follow these steps:
First, view your own profile, and find the module that has your friends in it, and click the “See All” Link
Then in the top right, look for the “Edit Friends” button and click it.
Then select “only me”
You can also select “custom” if you want to hide your friends from only certain people.
How do I go offline in Facebook Chat?
You can go offline (unavailable) to all friends, some friends or individuals:
To go offline to all friends: Click the icon at the bottom of the chat sidebar and select Go Offline.
To go offline to specific friends or friend lists: Click the icon at the bottom of the chat sidebar and select Advanced Settings. Enter the names of friends or friend lists you want to appear offline to next to the heading All your friends see you except.
Note: If you are online to chat but appear offline to friends, make sure that those friends aren’t included in a friend list under: All your friends see you except.
But how can you be invisible on Facebook to certain users? This is how.
How to put Facebook skins/background
locate the one setting used to control who can comment on your posts. Go to Facebook,click on “Account Settings,” and select “Privacy Settings.” On this page,click the “customize settings” link near the bottom as shown here: