Via DS Fanboy

Nintendo and Toys 'R Us are teaming up to hand out some virtual gifts through Animal Crossing: Wild World. The gifts available, which are implied to include Mario in one way or another, number six, however only one will be available to download per town. You'll have to trade for the others. The process with which to acquire one of said six items goes:

Insert your Animal Crossing: Wild World Game Card into your Nintendo DS. Power up.
Purchase Bottle Mail at Tom Nook's Shop.
Write a message and release your Bottle Mail into the river or at the beach. Save and end your game.
Visit the specially marked Animal Crossing: Wild Word promotion in the video-game section of your nearest Toys 'R Us July 23-30. At the main menu, tap Tag Mode.
Watch and wait for something to arrive in your town!
Restart your game and comb the beach for Bottle Mail containing a special rare item!
Let us know what you get!