I'd have to agree with the guy above me. They really should have cables packaged in with the game.
I have a GBA but I don't know anyone else who has one except my friend's little brother. I don't even have a cable for mine.
The thing is, my gamer friends and I are really looking for some good multiplayer games, and zelda would be really good, so I am looking forward to it, but we all still need to get the right equipment.