I've collected a ton of Gems for Shiroku Pub lady but i need stones for the higher lvl items(i think i got one from a quest which i then traded in for a sweet Flying Disc for my Yukiko).  How can i get more stones to trade for more uber weapons? 

The woman at the shrine at night trades fish for stones. She'll want one of each of the lower class fish (Goldfish, Ayu something, and another one I can't recall) and after you've given her those you'll be able to trade fish for stones. She'll want a certain fish for each type of stone though.

@OmegaChosen: Ah, i get it now! I remember giving her one of the fish i bought from Tanaka and that's when she gave me the bug net as well.

I was going to make a joke about kidney stones but it turned out that I just ended up researching kidney stones for like 30 minutes.

@Ravenlight: That comment made me remember when Joey had kidney stones in Friends....so I spent 30 minutes going through the box set to find that episode...

There are Rare Stones that can be traded for high level items in Persona 4:Golden?! I've been trying to convince myself to not buy a Vita just to replay Persona 4 in the Golden edition and now I hear crazy stuff like this and my will is weakening. Sounds like there is a bunch of new stuff!

Fish for stones.... Must. Resist. Purchasing. Vita!

Are there any items actually worth getting?

I know if you want to get all of the costumes you need Mondo stones, and you get +50% XP items from trading in stones, but anything else? I haven't seen anything on the list which rivals the endgame weapons.

@selfconfessedcynic: I think there's a point where the 2nd tier weapons on that list are stronger than anything else you could possibly have, and it is feasible that you could have the stones to trade for those items at that time. However, as far as I can tell, that's the only time that is true, especially late game, as you mentioned.

@Molenator85: I thought as much

Oh - and for those who want all the costumes, to get Mondo stones you need to catch River Guardians, so you need to have accepted the emma request for Hermit s.rank 9.