Rotate instantiate?

When you are instantiating an object, how do you affect the rotation of the new object(I know how to change its relative position, but I cannot seem to figure the angle out)?

You can use Transform.Rotate to rotate the object after it has been instantiated.

var tempObj : Transform = Instantiate(prefab, transform.position, transform.rotation);
tempObj.Rotate(0,20,0);

In this case, the object will be rotated 20 degrees around the y axis.