The "Chao duplication" Glitch can also be done with two memory cards. This is how to do it:
Put two memory cards into the Gamecube. Next, copy your Sonic Adventure Battle 2 file from the first memory card over to the second memory card. This will delete your Sonic Adventure Battle 2 file on the second memory card if you had one. Next, go to the Chao Garden (it does not matter which one, on which card) and go to the transporter (the big Game Boy Advance), select "Move Chao", and transfer whichever Chao you want from the second memory card to the first. If you do not want the file on the second, delete it. You can do this as many times as needed.
The "Re-Use animals in Chao Garden" Glitch can also be done with Chao Drives. However, it's a bit harder to do it because the 'Drives float in mid-air when dropped.
You can also have a clear picture in the PAUSE screen. To do this, pause the game, then hold the Y and X buttons.