Here is an easy to make case for your iPad, using some "free" supplies from a well known courier service. You can use the iPad while it is in the case. It is not padded but it should protect your device from light scratches.
Note: Use this case at your own risk. This case is meant for amusement purposes only and the amount of protection it provides should not be tested, at risk of any damage to your iPad. Also, please do not take advantage and abuse the amount of the complimentary shipping supplies. Thanks.
Step 1: Supplies
1 Clear, adhesive waybill pouch (with resealable zipper)
1 Large Tyvek envelope