don't list it anywhere for one..
now that it's out this might be too late.
You can always go to your privacy settings and block anyone who isn't on your list. I've had to use this option a few times after saying "If you dumped me, and you don't care at all, why do you IM me everynight?" a few thousand too many times. It's actually amusing when they call you a couple days later screaming at you for blocking them and you hangup, they call back and start saying stuff like "Well why did you call me then" to which your only response can be "look, you IM'd me, you called me on the phone, you are the one that just called me back." then you hang up the phone and leave it off the hook for the next few days.
If you've never had the fortune of being in this situation, it's probably because I'm a magnet for them