In reply to whoever it was that asked why do they need a magic key or passme to play from the GBA slot;
You dont anymore, a replacement DS firmware has been released allowing the booting of 'homebrew' code from the ds flashcard. unfortunatly you do need a passme to flash your firmware in order to do it though, but this is good news as now you only need 1 passme between a few people to flash your DS and in time i think the hacking of DS will be via firmware upgrades and not just via DS cards and adapters.
correct me if I'm wrong, but I believe you also need to solder 1 wire to allow writing permission on the firmware...
You don´t need to solder anything. As long as you short 2 points, you´re good to go.