On your iPhone or some androids there may be an option under wifi settings on the phone to set up a personal hotspot. If your phone is capable of doing it you'll see the option near the top. Click on it and under its option change the name to Bestbuy (America only, other regions have different names) and then set it to active. Connect your 3DS to the hotspot and it will work as if you were at a Nintendo zone.
I actually don't pay attention to stuff like Nintendo Zone or other online Nintendo stuff. I heard about this before I saw this thread, but due to my lack of interest, I wouldn't mind missing out. Besides, I'm done with collecting in-game.