DS "hacking" is really ez, just buy a $17.95 R4ds card and a micro SD card and you get to have any DS game you want.
it doesn't touch your firmware so you keep the warranty (if you have one still) You can get a 2gb and put on around 24 nds roms and still have room for homebrew. Homebrew ranges from games to apps like DSorganize which has web browser and IRC. Its worth it because you're not spending $30 for each game, Although nds ROMs usually are talked about on the net.