how to "rotate" the objects (trackball rotation)

I would like to know an easy way of rotate the polygons (when I move them with the mouse) that I am drawing (without GLUT).
The problem is that the rotation has to be referred to the local object coordinate system.
When the object was “upside-down”: moving the mouse to the right caused an apparent left rotation and vice-versa.
I have found some information about trackball rotation but I am looking for something easier (without quaternions…?).

If you just adds the mouse movement to the objects rotation do I think it should be right.