Dark shades.  Leather jacket.  Smug expression.  Ashton Kutcher, u r 1 kewl dude.  We spotted The Kutch outside of The Late Show with David Letterman last night who was there to talk about his new movie What Happens in Vegas.  The romantic farce co-starring Cameron Diaz about what happens when two people get drunk and then get a quickie wedding in Sin City opens this Friday.