Turtle Beach offers a number of headphones for different consoles and PC, so it comes as no surprise that the DS gets one too. It actually gets three, coming in black, white, and pink - just so you are color coordinated with your DS Lite.
It is worth noting that these headphones work for the less fortunate "fat" DS owners out there.
Nintendo may be offering a mic when it releases Pokémon Diamond/Pearl, but the Ear Force D2 gives you both a mic and a headset in one, and is available now.
The DS has a couple games that make use of the mic for Voice over IP (VOIP). Metroid Prime Hunters and the recently released Custom Robo Arena, plus the above mentioned Pokémon games.
The Ear Force D2 is a comfortable set of headphones with adjustments for the mic and head strap. When not using the mic, you simply swivel it upwards. The cord also has a volume adjustment dial.
Many people don't use headphones when playing the DS, and that is a crying shame, considering the wonderful sound design in this generations of games.
The Ear Force D2 allows you to enjoy the game music the way it was meant to be enjoyed, and use the mic functionality in DS games, all in one package - for under $20. This is a pretty good deal.
And while it won't help you say "blue" any in Brain Age, it will help with the stares you get when talking to your DS.