I know you can get like custom programs to run on the Nintendo DS, like the fan-made DS port of DOOM, and various others. However, I don't know how to get those programs and stuff. Do I need to buy some sort of card or something that I can put the files on, and then put that card into my Nintendo DS Lite, or what? Or is there a way to download the files from your computer directly to your DS (perhaps via the Nintendo DS WiFi USB adapter, or via WiFi, or something)? If I do have to buy some sort of special cartridges or something, then where can I buy them?