Christmas cards! They're the ones people send to their relatives they haven't talked to all year, just to say Merry X-mas, right? From your description it sounds more like kids addressing letters to Santa! By the way, you may know that in American Christmas lore Santa Claus lives on the North Pole, but for British kids he lives in ... that's right, somewhere in Finland! Could that maybe explain the crazy address issues you've had to deal with?