Retrieve profile picture using Facebook SDK 3.0 for Android

I've following problem with Facebook SDK 3.0 for Android. I wanna get my (and my friends) profile picture without using their ProfilePictureView widget, so if I use Graph Explorer I see that Json response is:

{
   "data": {
         "url": "https://fbcdn-profile-a.akamaihd.net/hprofile-ak-ash4/372127_1377011138_1538716206_q.jpg", 
         "is_silhouette": false
    }
}

I need that "url" path to download and show the picture, but with the following code:

Request.executeGraphPathRequestAsync(Session.getActiveSession(), 
                                     "me/picture", 
                                      new Request.Callback() {
        @Override
        public void onCompleted(Response response) {
            GraphObject go = response.getGraphObject();
            Log.i("APP_NAME", go.toString());           
        }
});

I obtain this:

GraphObject{graphObjectClass=GraphObject, 
    state={"FACEBOOK_NON_JSON_RESULT":"����\u0000\u0010JFIF\u0000\u0001\u0001\u0000\u0000\u0001\u0000\u0001\u0000\u0000��\u0000"}}

Someone can help me please? Thanks

Cromir