For those who'd like even more of a challenge, just delete your Facebook [1]. They'll instantly deactivate (not delete) your account, and then spend 7 days sending emails which are designed to make you change your mind, with various psychological tricks.
I am already off Facebook since a few months. The first 2 weeks I caught myself opening a new tab typing 'face' and then realizing I deactivated my account. I just moved to a new city which breaks my old ties even faster. But my really good friends call me now and that feels really good!