Nintendo DS Headset
Use the Nintendo DS Headset to talk/chat over the Nintendo Wi-Fi Connection with games like Pokémon Diamond or Pokémon Peal (all players need a copy of the same game and must register each others friend code) - or use with voice command games like nintendogs.
Nintendo Wi-Fi USB Connector
The Nintendo Wi-Fi USB Connector enables you to connect the Nintendo DS to the Internet via a PC. You can use this to play Nintendo DS games online that have been especially designed for Nintendo Wi-Fi-Connection.