On the Pokémon Global Link, you can have Game Pals on your profile, made up of Friends and Trade Pals. Trade Pals are pretty straight-forward, but I can't figure out how to add someone as a Friend. It says to add them in your Pal Pad in-game on the system they conect to the internet with, but I did that. My friend still isn't showing up in the roster though. Is there anything else you have to do?
If you add a Friend Code manually (that is, entering the code number by number instead of adding a Friend Code using infrared), just adding the code isn't enough: You have to meet at the Wi-Fi Club. It's not necessary to trade or battle; just being online at the same time will do (it happened to me). Maybe it'll also work if you trade/battle using infrared, or something like that, but I don't really know for sure. You can check if you truly have a friend registered by checking your friend roster: if you can see their icon and name in color (blue or red), your friend is registered; if their name is gray, then it doesn't count as registered, since you haven't really connected in any way.