What is your best practical Joke?

My sister was coming into town for a wedding and the whole family went to pick her up at the airport. She told me over the phone that her husband, a Pediatric Surgeon, had just bought her a 3 carat diamond ring. My uncle was a watchmaker; so when my sister got off the plane she was greeted by a dozen relatives, all with jeweler's eyepieces at the ready to inspect her diamond. She tried to get back onto the plane she was so embarrassed