Who knew a Southie from Boston could a do such an effective Texas Accent? Not me. Last night on Letterman, The Departed star ad-libbed McConaughey’s southern charm and willingness to appear shirtless in some behind-the-scenes commentary. To my knowledge, Damon has never worked on a flick that required him to learn some Texas slang. So this is no pre-packaged Brokeback accent. The man’s got talent. Just admit it.