Success have the Wifi Adapter from Nintendo for use on Amimal Crossing and More importantly Mario Kart DS.

If you love Mario Kart DS and you rate yourself then the adapter will let you play from anyone around the world, its an essential DS Purchase. Heres the info:

This USB connector is for those who don't have a wireless Internet connection, the adapter can plug in to a computer's USB port to create a Wi-Fi connection with the DS. Users can then use this to play compatible Nintendo DS games online.