Duplication Glitch

There is vid that sums it up bellow,
Basicly you need to have 2 devices have one device join the others game, and both need to be looking in the same chest, if you put one item in and have both devices take it out at the exact same time, the item is now duplicated and in both of the inventories. You can do it on the corent version 0.6.1. Thanks!! I am hoping you guys can fix it

http://minecraftpecheats.com/2013/03/18/minecraft-unlimited-items-cheat/