_ http://help.adobe.com/en_US/AS3LCR/Flash_10.0/flash/display/Graphics.html#copyFrom()
var circle_original = new Shape();
var ctx = circle_original.graphics;
ctx.beginFill(0);
ctx.drawCircle(0, 0, 10);
ctx.endFill();
var circle_dupe = new Shape();
circle_dupe.graphics.copyFrom(circle_original.graphics);