I don't do long haul but our company is bound by a directive introduced by the UK CAA that the flightdeck is out of bounds to everyone except personnel that have a genuine operational reason for being there. Not even staff going on holidays are permitted.
On the shorthauls sadly we are forbidden to allow passengers into the flightdeck. I don't know of anyone that breaks the directive as
a) rules, particularly in aviation are not to be broken and
b) there are too many wanabee journalists waiting to sell the earthbreaking story to the papers that a 5 year old child was allowed up to the flightdeck on their flight yesterday and all the passengers panicked and thought they were being hijacked!!!
It's sad as it was a great to interact with the pax and when I was younger I used to love to go up to the flightdeck but this is 2002 and the world we live in today.
ES