Sunday is 4/20, the informal national holiday of stoners (and, yes, mellow-harshingly, Hitler's birthday). While some dedicated weed-aficionados will celebrate by playing hacky-sack at peach rallies, most will wake, bake, and stay on the couch all day chasing the DVR dragon. And don't think the programming departments of cable channels haven't caught on. While Comedy Central has been featuring 4/20 ...