How to disable Facebook Timeline and get the old profile back

When Facebook Timeline was announced, it didn't take long for the Internet to figure out that even though the new profile design isn't yet available to the public, anyone could get it immediately with this little hack.

Today, over 1.5 million users have activated Timeline with this workaround, making the new profile visible to each of them and anyone else who has enabled it.

Eventually, Facebook will mandate Timeline for everyone, and when that happens, expect a lot of backlash. Many people, even those who opted in to the new design, seriously dislike it. They're calling it narcissistic, cluttered, and creepy.

If you concur, and you were one of those people who enabled Timeline, there's still a way to enjoy the old profile design (while it lasts.)

Step 1: Head to the Facebook Developers page where you originally created an app to enable Timeline. Click "Edit app."

Step 2: The only way to remove Timeline is to delete the app. If you are an actual developer, you're out of luck. Otherwise, click "Delete app" in the left sidebar.

and 

Once you confirm the app deletion, your Facebook Timeline will be disabled.

Editors' note (December 19, 2011): This method for removing Timeline only applied to those who enabled it before its public release. Now that it's being rolled out to everyone, there is no way to remove Timeline and revert back to the old profile.

source: http://howto.cnet.com/8301-11310_39-57333231-285/how-to-disable-facebook-timeline-and-get-the-old-profile-back/