When I get really mad at someone, I usually take some time for myself and when cooled off, proceed to talk it over with that person. That’s me and I realize that other people handle things a bit differently. The cold shoulder. Prank calls. Broken windshields. For the latter, there is PoopSenders.com, a web site that allows you to anonymously mail up to a gallon of cow, gorilla, or elephant dung to that special person in your life.
Note: Some have reported that this site is a scam.