Handles.FreeRotateHandle
static function FreeRotateHandle(rotation: Quaternion, position: Vector3, size: float): Quaternion;
static Quaternion FreeRotateHandle(Quaternion rotation, Vector3 position, float size);
static def FreeRotateHandle(rotation as Quaternion, position as Vector3, size as float) as Quaternion
Parameters

rotation Orientation of the handle.
position Center of the handle in 3D space.
size The size of the handle.

Note: Use HandleUtility.GetHandleSize where you might want to have constant screen-sized handles.
Description

Make an unconstrained rotation handle.

The handle can rotate freely on all axes.


FreeRotate handle seen in the Scene View.
	// Create a simple rotate handle (half scale) on the 
	// target object that lets you freely rotate
	// the Object Without having to select the "Rotate" button
	
	@CustomEditor (FreeRotate)
	class FreeRotateHandleJS extends Editor {
		function OnSceneGUI () {
	        target.rot = Handles.FreeRotateHandle(target.rot, target.transform.position, 0.5);
	        if (GUI.changed)
	            EditorUtility.SetDirty (target);
	    }
	}
And the script attached to this Handle:
	@script ExecuteInEditMode()
	
	var rot : Quaternion = Quaternion.identity;
	
	function Update () {
		transform.rotation = rot;
	}