Patch Removal
When you remove the Xbox Live patches, you can do all the glitches that were patched, but this removes the patches for all of your games. No saved game data will be lost, but you will need to repatch everything when you sign-in to Xbox Live, as well as risk being stranded in a modded map that was removed.

Go to the system blade on the dashboard. Select memory and push the GREEN button.
Select hard drive. Press YELLOW to view device options.
When the page opens press BLUE, BLUE, LB, RB, BLUE, BLUE.
A message, "This will perform maintenance on your xbox 360 storage devices. Do you want to continue?" Select "yes" and press GREEN to execute.
Restart your Xbox 360 with the uninstall.

Cheat - Duplicate Items (Post Patch)
This cheat duplicates items in a similar way to the pre-patch method using a bow and arrows. I have seen variations on this method involving swinging weapons/fists but found they did not work (on the PC at least). This method works with Shivering Isles installed and is more straight forward than the old method.

To start with you will need at least 2 identical scrolls. Open you inventory and equipment them. Click on the scrolls once more, then drop the item you would like to duplicate. The quantity of the item needs to be less than the number of scrolls, for example if you have 10 scrolls the number of items duplicated at one time has to be 9 or less. Exit your inventory screen and the duplicates will fall to the ground. The number of items duplicated will be equal to the number of scrolls. To repeat this go back into the inventory screen and click on the equipped scrolls and drop the item to be duplicated (no need to unequip and equip the scrolls)

This method does not duplicate stolen items and some rare/quest items. It is however useful for duplicating light, valuable items such as gemstones which can be sold.

Cheat - Item Duplication (Post-S.I. Patch)
Unverified. To duplicate items after downloading Xbox 360 Shivering Isles expansion pack do the following:

1. Equip a Scroll that you have multiple of (for example, Minor Heal Other x10). If you have ten scrolls you will get ten items.

2. Swing a weapon, and before the animation is over go to your inventory.

3. Select the equipped scroll and press GREEN twice (you won't get a message)

4. Drop the item you want to be duplicated. Note: you can only duplicate things that you have less than the amount of scrolls you equipped. So for example with ten scrolls, you cannot duplicate a potion where you have eleven bottles of. To get around this just drop a few of the items you want to duplicate before you start this glitch so you have fewer items than the amount of scrolls that you have.

Hint - Free Iorn Arrows
Go to the arena in the Imperial city and watch the blue team archer shoot arrows. Half the time you can go in there, the arrows the archers shoots will be there and you can simply take them without being labelled a thief. Naturally, you may want to save before attempting this.