there used to be a raid addon that put markers on the playing field long time ago durring Wrath.. what it did was tell you range(on playing field you would see a line drawn out) and also you could add boxes on the group in the room or area around the boss for people so they would know where to stand. this addon was disabled dude to the "cheat" that it used on making fights more easier ... i think it had to do with an API build in the bliz that bliz shut down so that addon didnt work....
Like i said it let you draw ingame on your screen..
Anyone know the name of it that would be awesome
http://www.youtube.com/watch?v=nsRntT7EmZk