To be honest I'm not sure what I'm saying, as I only read about this online this afternoon... but there are a few websites (if you Google it) that claim Cobb is wearing his wedding ring in every dream scene, and not wearing it in any 'real world' scene. If it's not his totem, then it's dream / non-dream tell, maybe? Something to chew on, perhaps? EDIT: Isn't the spinning top flawed as a totem, since his wife had used it before him? Perhaps this makes the scenes where Cobb is using the top more about his own inner turmoil than truly telling the audience what's what.