Wow. I just discovered a great use for Earthquake and this one kicks ass for running 5 shammys. Change one of your views so that all 5 shammys use the same view except at a 72 degree rotation. Now as long as your guys are facing close to the same direction, you can place 5 earthquakes in a pentagram around yourself.

Doesn't seem that useful at first, however, for those annoying rogues in bgs that love to play the sap game, this will pull them out of stealth rather quickly and reliably.