i really need one bad
There are Wi-Fi events for Jirachi, although they have since passed. The best way is to have a friend with Jirachi trade one to you. You can then trade it back to them, but now Jirachi is on your Pokedex. This allows you to be able to get it on GTS.
If you get pokemon channel on gamecube and complete it you can send on Jirachi to a pokemon Ruby Emerald or sapphire :)
Type a Pokemon name, type, move, ability to see instant results.