When I flew to Xi'an from HK on KA I got a chance to go into the cockpit probably because:
1) both crews (cabin and flight) were bored on the 3-hr flight with no IFE except for newpapers and magazines;
2) both groups had finished their meals and had nothing to do

Pretty nice, the A320 cockpit is. I even got the chance to see a couple of planes cruising below us ^

Note: this was after CX had 'swallowed' up KA, and was the first KA flight eligible for Asia Miles.