Try humor. If someone has ticked you off, there must be something humorous about it, right? A good laugh often dispels some of the worst moods.
Another thing that I found helpful when I had some serious anger issues over a truly serious wrong was a drill from Donna Eden's "Energy Medicine" called "Expelling the Venom." I've seen similar drills in QiGong.
No matter how seriously you've been wronged in an incident, there is no point in wronging yourself still more by carrying that anger around.
