Other than the feather (Phoenix Down), you can revive characters with all healers, arcanist/summoner, redmage (if they have the level for it, they get it at 64), and blue mage (if they have the spell(s) on hand). And, if you yourself are not in combat and you are not in an instance and you do have one of those jobs, you could switch and then revive. I sometimes do that if I am out and about gathering things and see someone dead/dying.

Levelling WHM or Arcanist to 12 would give you access to that option quickly, if you'd like it. Just keep in mind, not to try to switch to your low level healer, if you are in an area way beyond it and near some mobs or you'll join that corpse. :P