3 or more people sit in a circle. As the game begins everyone is "Harry" (although this will change as the game continues). Choose someone to start. This person is player 1. Each player is numbered to the left but only for the purpose of explaining the game.
Player 1 says to the person on their right, "Hi Harry". Player 2 then says "Yes Harry?". Player 1 then says "Tell Harry Hello", referring to the person 2 spots away from player1 (this would be player 3).
The play continues. Player 2 now says "Hi Harry" to player 3. Player 3 then says "Yes Harry?". Player 2 then says "Tell Harry Hello" referring to the next player in the circle beyond player 3.
This continues around the circle until someone makes a mistake. Speed up as necessary. When an error occurs, get out the peanut butter and put a spot of peanut butter on the nose of the screw up. They are now no longer "Harry", but instead should be referred to as "1 spot".
So if the 1 Spot player is in the "player 2 position", player 1 would say "Hello 1 spot". 1 Spot says "Hello Harry". Player 1 says "Tell Harry Hello. 1 spot then says "Hello Harry". "Hello 1 Spot". etc etc. If a person with 1 spot screws up again they get a second spot of peanut butter on the face and are now referred to as "2 spot". This is why it's important to make the peanut butter spots visible so that people know what you are.
This continues until someone gets 4 spots and they are out, but you can keep playing. the speed should increase throughout the game.