I am too nice to you guys.
var AMOUNT = 20; //adjust based on how much you want the movieclip to shake
function makeMcShake(which:MovieClip){
which.defaultPos = {which.x, which.y}
which.addEventListener(Event.EnterFrame, shake);
}
function stopMcShake(which:MovieClip){
which.removeEventListener(Event.EnterFrame, shake);
which.x = which.defaultPos.x;
which.y = which.defaultPos.y;
}
function shake(e:Event){
e.currentTarget.x = e.currentTarget.defaultPos.x + Math.rand() * AMOUNT - AMOUNT / 2;
e.currentTarget.y = e.currentTarget.defaultPos.y+ Math.rand() * AMOUNT - AMOUNT / 2;
}