M3 Adapter has now released the PassKey 2, compatible with all Nintendo DS consoles.
M3 Adapter is made for those who want to download freeware games, movies and music from a PC to a GBA(SP) and/or Nintendo DS. You can use your PC and normal Compact Flash Card Reader to transfer and convert you movie & music files to the Compact Flash Cards. Then, insert M3 Adapter with CF/SD Card into GBA(SP) or Nintendo DS, and the files will be available after boot up of the console.
Its features are just the same as any other MP3 Player on the market but also playing games and movies instead of playing music only.
One of the coolest features of an M3 Adapter is that you can directly run third party software on it – that includes emulators of the video game system.