I don't have much info on this as I stumbled onto this by accident but I managed to get USB Mass Storage to work without rooting or programs via a 14 inch long USB cable that I had squirreled away long ago. It doesn't have any numbers just a thin green line running on its center. Its probably from an older Samsung Model cell as the connector was the same and has the little hooks to stay mounted when connected. I've included some photos and hope someone can identify it properly so that others with their S III can rejoice at not having to swap out the card or afraid of rooting their phone.

I hope this helps anyone with their S III!