teeny tiny bump :3
Found "Infinite Diamond" on the Minecraft forums, So I copied it and want to show it to you:
it's rather simple, but i do hope notch fixes this soon.
to do this, you need a furnace and at least one diamond.
first, activate the furnace, and click your diamond so you're holding it.
then press the inventory button and pick up the dropped diamond.
next, activate the furnace.
click an empty space in your inventory, and OMFG FREE DIAMOND!!!
yeah....
notch needs to fix this...
EDIT: you can use this from any inventory.