Center of Mass/Gravity Indicator

I don't know when I first saw it (it may have been years ago now), but I've noticed that there is a little blue circle indicating the center of mass of my part that is always visible while I'm modeling.  While this is a very useful feature when you need it, I don't need to see it ALL the time.  Does anyone know of a way to turn this off?  By the way, I'm using SW 2010.