I use a randomly generated password from LastPass. I have no idea what it is, so I can only access it from my laptop (with the Firefox LastPass Add-on). That combined with LeechBlock is pretty effective.

I could go to the LastPass site on another machine, I suppose. But I do store other, more important passwords on LastPass and don't want to expose those. And it takes only nominal inconvenience to prevent me from jumping into FB.