I used to be very short tempered and just say nasty things. Now it takes a lot for me to lose control but when I do get pissed its usually for a good reason and I follow a rational reaction with a not so rational one.
Example: Last summer, my then-girlfriend came to visit me and stayed for a week. One night we went to a friend's house and everyone got ridiculously drunk. It was a smallish party, so we were all just planning on crashing there since his dad is a cool guy. At one point, my girlfriend and another girl were making out (woo hoo) and my friend (the guy whose house it was) comes up and tries to join in. At first, I thought he was trying to hook up with the other girl, but then I realize he was making out with my girlfriend. I fucking flipped. In one motion, I pushed her away from him, grabbed him by the neck, and held him up by his neck against the wall in a less than gentle manner. I told him if he ever tried anything like that again, he was going out the window, to which he said "yeah, and I'd deserve it". So I let him go, and then grabbed my keys and tried to go drive (thus the irrational version of me setting in). Thank God for the fact that I have awesome friends and they literally stood in front of my car and wouldn't let me drive anywhere.