Messing with strangers when they don't realise it is most hilarious, try to contain your laughter as you make people do what you want without them knowing it.
WHERE: Public transport, board meeting, preferably where others are facing you.
WHO: Strangers and friends
WHY: For kicks
A most amusing trick while being bored to death on the train or in a PBL* is to scratch or rub your nose lightly and watch how many people do the same. It usually takes a maximum of three seconds for the people across from you and beside you to follow suit.