The Killing Club by Marcie Walsh and Michael Malone

Eleven high school outcasts create a club that came up with ingenious ways to murder those who annoyed or hurt them.  A decade later members are dying in the way they once stated they would murder their enemies.  At first no one remembers but as the bodies start piling up it becomes obvious no one in the club is safe.  Great story leaving you guessing until the end.  290 pages paperback.