Python is now on Youtube, in hi-def. I'd hoped someone would submit the above vid first, so everyone understood. Expect half the vids on that channel to make it here.
There is a way to not laugh, but I don't recommend it because it means being a wet blanket: remember that Michael Palin's character can't help his speech defect and his feelings would be hurt if he realized people were making fun of him.
Great Palin scene. It's amazing he pulled it off as well as he did considering the infamous trouble he admits he has with keeping a straight face during stuff like this.
Also, not really a dupe. This is the official channel version of this scene which means better quality and it won't get taken down.