The worst part about that feeling is knowing that every minute you're angry, is another minute the other person has the advantage over you. And while you know that, you can't change it.
I like to write letters that I will never send. It's a good chance to just get it all out on paper. And then, if you have a safe place, burn it.
The Justin Timberlake approach is the best one. What comes around really does go around. People are petty and small minded always get theirs, even if getting their just means they have a boring, stupid, and totally un-fun life. I mean, Justin's life looks great, plus he acts like a big dork and is clearly having a lot of fun. Even if he weren't Justin Timberlake, a person like that is always going to be asked to parties, do well at work, and all that good stuff because he's nice, and he's nice because he's not weighted down with dumbness.
So, focus on your personal freedom from nonsense!