Since I got kicked out of Facebook, I am signing up for Enemybook, the most brilliant concept on the Web since Gophers.
Here's how they describe it:
Enemybook is a Facebook app that allows you to manage your enemies as well as your friends. With Enemybook you can add people as facebook enemies, specify why they are your enemies, notify your enemies, see who lists you as an enemy, and even become friends with the enemies of your enemies. Ever wanted to "enemy" somebody instead of friend them? Finally you can. This app remedies the one-sided perspective of Facebook.
Keep your friends close, and your enemies closer...
Oh, crap. Now I see that I need to HAVE a Facebook account to make this work. The Universe is so unfair.