Beyond blowing at your DS to inflate bubbles in Nintendogs, other games make interesting uses of the microphones: Spectrobes:
"dark energy creatures called the Krawl, and they're now invading your system. The only way to defeat them is to excavate and reawaken ancient creatures that are buried deep underground, called Spectrobes. (...) minigame and involves making a certain level of noise, with the tone and pitch of that noise playing a part in deciding what kind of Spectrobe you will get once the process is complete."
"Dragon Tamer: Sound Spirit is basically your standard Pokemon monster battling game, but in order to get new dragons, you record sounds from different instruments and sources with the DS mic.
This is kind of like what Monster Rancher for the Playstation, where different random CDs would generate monsters with different statistics and abilitie"
Why do I blog this? interestingly enough, the mobile game industry, which has the perfect affordance and habits to control things with the voice (i.e. a cell phone...) has never released something similar (although I've seen some prototypes) on mass markets. Interesting HCI anyway... and on the NDS, as usual.