Distributed item

Distributed items are items sent to the player from Nintendo using the Nintendo WiiConnect24 system. The items are linked to real-time events in the real-world which do not exist in game, such as St. Patrick's Day which exists in the real-world but doesn't appear in as a celebrated event.

Distributed items are scheduled to be released during a 7-day period, where the item is received within the allotted time. Pete, the mail carrier, gives the player an item attached as a present on a letter. He will mention that the letters are from Nintendo, but some may be signed by special residents or out-of-game characters that appear in other Nintendo games. Sometimes Wendell will give the player one of his designs to commemorate a special occasion.

In order to receive a distributed item, the player needs to have WiiConnect24 enabled on both the Wii and in the game.

Current Distribution
http://us.wii.com/images/games/animal_crossing/item1.jpg

From U.S. Nintendo Website.