You get a pokenav instead of a town map. at rustboro you meet a man (the same man you saved at petalburg woods) who needs you to get something back from a team aqua dude. you fight the aqua dude in a tunnel and you also save a wingull named pecko. You give the things back to the man, and he'll lead you to the leader of devron corp. He'll tell you to deliver the package and give you a pokenav along with the quest.