Hamlet Defence.

[Estellios]

Hopefully when all 3 hamlets are available they will all rotate "active battle" status. The bonuses you get for turning in items could make it still valuable to participate in the non-battle phase. Anima bonuses are great too =P

Keep in mind that even if you don't have a crafting or gathering class, you can turn in any gear with materia on it, or just buy the turn-in items if they are on sale. Junk gear you get from stronghold chests attached with materia you don't need are ideal. Don't forget that you can have people attach materia while you are afk through the bazaar now.