The developer behind a series of popular game console emulators for Android such as the Tiger GBA Emulator and Tiger SNES Emulator has released the first working Nintendo DS emulator available in the Android Market. Unfortunately, working is putting it a bit strongly.
Tiger Lab can open Nintendo DS ROMS, but it’s extraordinarily slow at this point. The developer recommends only trying the emulator on high-end phones, and sticking with small games without 3D graphics. He expects it could be another year or two before a truly usable DS emulator is available for Android devices — and it will likely take more powerful phones as well as software enhancements to get there.
That said, if you want to get a glimpse of the future, Tiger Lab is available as a free download from the Android Market.