Here is the collection of bloopers (shots behind the scenes) from F.R.I.E.N.D.S. There are lots over YouTube. Just search for Friends Bloopers.
This is a deleted scene from F.R.I.E.N.D.S. This scene takes place in an airport where Chandler and Monica are misunderstood as terrorists. This scene was to be aired two weeks after the Sept 11, 2001. After the WTC incident, the producers decided not to air the scene.