Never seen one of these before but it was outside my house in Savannah, GA.
CLOSED: What is this bug?
I think it might be a juvenile "Wheel-bug"; if so it is a predator. I believe that this is in the order Hemiptera (True Bug's). Good addition to the landscape.
Second that - see http://entnemdept.ufl.edu/creatures/trees/wheel_bug.htm