Well there is an official way where you use your ftp and set up a new connection to your ip address (Go to wifi settings and click the blue arrow next to your wifi connection and the ip connection is written) and for username: root password: alpine . Then you connect then you need to make a folder called ROMs and inside that folder make another folder called GBA. Then you drag all your .gba games into the GBA folder.
There is another way by installing ishare from the installer and making a sendspace account. You need to make the folder ROMs and GBA from the ftp though, but with ishare you can upload .gba games to your sendspace account (from your computer) and download it into your directories in your itouch (Inside the GBA folder of course. There's a browser so don't worry).
