Hey, I just saw two people today in Valkurm Dunes, walking in the ocean, not the Siren Sand's one (White bones perhaps...if thats the name).
It would be great if someone could tell me how to do that, because from what Chewy and Lastslinger on fairy said, there's some Private beach that you can reach with the glitch.
This may seem impossible, but trust me, it's VERY possible as I seen it myself. I also thought it was a debut for scamming in FFXI, since they were selling the information for 1,000,000 gil.

But WTF?, I pity those who gave them money for the information...