There could be many opportunities to get to literally get to know myself better. I could also mess with people. But on a serious note, I could double my productivity if I can motivate my clone enough. I am assuming the clone is a physical and mental copy of course. I would also love getting into conversations with it about our separate experiences throughout the day. On a not so serious note I could even watch multiple football games without changing the channel. All I'd have to do would be shout across the house and hear my own voice call back the score.