For those of you looking to connect bluetooth devices to your Nintendo DS (for whatever reason), there IS a way. It’s not easy but you can do it following this great articles on how to make a DS Bluetooth adaptor.
In our design, we use a tiny ATmega168 microcontroller to make the Nintendo DS speak to the RN-41 Bluetooth SMD module by Roving Networks. Using this piece of hardware the Nintendo DS can scan its neighbourhood and establish connections to other Bluetooth devices (supporting SPP). The module can also be remotely connected to, allowing for a range of interesting applications. We also developed a software library for the Nintendo DS, making it easy to use this new Bluetooth interface.