Cosmo Canyon - Back Room
After Meteor has been summoned, return to Cosmo Canyon and visit the Item Store (to reach it, climb up the ladder to the far right outside on ground level). There was previously a rope barring a path that lead around to the back of the store, but now that it's disappeared, follow the path around. You'll find yourself in a room with the "Fullcure" materia and two other items.
If you don't find Cure 3 or White Wind effective enough, you might like to use Fullcure.
Added by: Volke Jan 31st 2009, ID#13623