Divineo USA have stuck on their website the latest Passcard for the DS, basically you have this and a cartridge in the GBA slot and you can play homebrew on your Nintendo DS.

Heres the details:



Passscard is the perfect flash card boot-up solution for DS LITE & NDS . It is compatible with most types of flash cards including M3, Neo, SC & G6 etc.

Plug & play! Simply insert both PASSCARD & flash card into the slots of NDS and that's it: Music, Movies, Freeware, Homebrew and other files stored on your flash card can be launched.

More info at Divineo USA