From the ArcaMax Publishing, Trivia Newsletter:
http://www.arcamax.com/news/trivia/s-476507-890188
The Germans do not typically serve potato salad cold, but warm or at room temperature. This reportedly aids in digestion. According to cooking show TV host Ursula, one way to rid yourself of a houseguest who has overstayed his welcome is to serve him ice-cold potato salad straight from the refrigerator. She claims it will upset his stomach, prompting him to think something is wrong with your food, and he'll leave sooner than intended.
This news arrived on: 01/11/2009